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PART 3


X(401) = BAILEY POINT

Trilinears       f(A,B,C) : f(B,C,A) : f(C,A,B), where
                        f(A,B,C) = [sin 2B sin 2C - sin2(2A)](csc A)
Barycentrics  g(A,B,C) : g(B,C,A) : g(C,A,B), where g(A,B,C) = sin 2B sin 2C - sin2(2A)

X(401) lies on these lines:
2,3   50,338   97,276   248,290   264,577  287,511   323,525

X(401) = anticomplement of X(297)
X(401) = X(I)-Ceva conjugate of X(J) for these (I,J): (287,2), (511,385)
X(401) = crosspoint of X(276) and X(290)
X(401) = X(2)-Hirst inverse of X(3)


X(402) = GOSSARD PERSPECTOR

Trilinears       f(a,b,c) : f(b,c,a) : f(c,a,b), where
                        f(a,b,c) = p(a,b,c)y(a,b,c)/a, polynomials p and y as given below

Barycentrics  g(a,b,c) : g(b,c,a) : g(c,a,b), where
                        g(a,b,c) = p(a,b,c)y(a,b,c), polynomials p and y as given below

In A History of Mathematics, Florian Cajori wrote, "H. C. Gossard of the University of Oklahoma showed in 1916 that the three Euler lines of the triangles formed by the Euler line and the sides, taken by twos, of a given triangle, form a triangle . . . perspective with the given triangle and having the same Euler line." Let ABC be the given triangle and A'B'C' the Gossard triangle - that is, the triangle perspective with the given triangle and having the same Euler line. The lines AA', BB', CC' concur in X(402), named the Gosssard perspector by John Conway (1998). Barycentrics for X(402) were received from Paul Yiu (2/20/99); the polynomials p and y referred to above are given as follows:  

p(a,b,c) = 2a4 - a2b2 - a2c2 - (b2 - c2)2

y(a,b,c) = a8 - a6(b2 + c2) + a4(2b2 - c2)(2c2 - b2) + [(b2 - c2)2][3a2(b2 + c2) - b4 - c4 - 3b2c2]

X(402) lies on this line: 2,3


X(403) = X(36) OF THE ORTHIC TRIANGLE

Trilinears       f(A,B,C) : f(B,C,A) : f(C,A,B), where f(A,B,C) = (sec A)(1 + cos 2B + cos 2C)
Barycentrics  g(A,B,C) : g(B,C,A) : g(C,A,B), where g(A,B,C) = (tan A)(1 + cos 2B + cos 2C)

X(403) lies on these lines: 2,3   112,230   115,232   847,1093

X(403) = midpoint between X(4) and X(186)
X(403) = reflection of X(186) about X(468)
X(403) = inverse of X(24) in the circumcircle
X(403) = inverse of X(4) in the nine-point circle
X(403) = inverse of X(378) in the orthocentroidal circle
X(403) = X(113)-cross conjugate of X(4)


X(404) = HARMONIC CONJUGATE OF X(21) WRT X(2) AND X(3)

Trilinears       f(a,b,c) : f(b,c,a) : f(c,a,b), where f(a,b,c) = bc(a + b + c) - a(b2 + c2 - a2)
Barycentrics  g(a,b,c) : g(b,c,a) : g(c,a,b), where g(a,b,c) = abc(a + b + c) - a2(b2 + c2 - a2)

X(404) lies on these lines:
1,88   2,3   8,56   10,36   31,978   46,997   57,78   60,662   63,936   69,1014   81,386   104,355   108,318   145,999   149,496   603,651   612,988   976,982


X(405)

Trilinears       f(a,b,c) : f(b,c,a) : f(c,a,b), where f(a,b,c) = bc(a + b + c) + abc cos A
Barycentrics  b + c + (1 + a)cos A : c + a + (1 + b)cos B : a + b + (1 + c)cos C

X(405) lies on these lines: 1,6   2,3   8,943   10,55   56,226   58,940   63,942   284,965   329,999   756,976   846,986

X(405) = inverse of X(442) in the orthocentroidal circle
X(405) = complement of X(377)


X(406)

Trilinears       f(a,b,c) : f(b,c,a) : f(c,a,b), where f(a,b,c) = bc(a + b + c) + abc sec A
Barycentrics  b + c + a(1 + sec A) : c + a + b(1 + sec B) : a + b + c(1 + sec C)

X(406) lies on these lines:
2,3   8,1061   10,33   37,158   92,1068   108,388   208,226   261,317

X(406) inverse of X(475) in the orthocentroidal circle


X(407)

Trilinears       (v + w)sec A : (w + u)sec B : (u + v)sec C, where
                        u : v : w = X(21); e.g., u = u(A,B,C) = 1/(cos B + cos C)

Barycentrics  (v + w)tan A : (w + u)tan B : (u + v)tan C

X(407) lies on these lines: 2,3   12,228   65,225   117,136

X(407) = crosspoint of X(4) and X(225)


X(408)

Trilinears       (v + w)cos A : (w + u)cos B : (u + v)cos C, where
                        u : v : w = X(29); e.g., u = u(A,B,C) = (sec A)/(cos B + cos C)

Barycentrics  (v + w)sin 2A : (w + u)sin 2B : (u + v)sin 2C

X(408) lies on these lines: 2,3   73,228


X(409)

Trilinears       u2 + vw : v2 + wu : w2 + uv, where
                        u : v : w = X(21); e.g., u = u(A,B,C) = 1/(cos B + cos C)

Barycentrics  a(u2 + vw) : b(v2 + wu) : c(w2 + uv)

X(409) lies on these lines: 2,3   65,1098


X(410)

Trilinears       u2 + vw : v2 + wu : w2 + uv, where
                        u : v : w = X(29); e.g., u = u(A,B,C) = (sec A)/(cos B + cos C)

Barycentrics  a(u2 + vw) : b(v2 + wu) : c(w2 + uv)

X(410) lies on this line: 2,3


X(411)

Trilinears       (1/v)2 + (1/w)2 - (1/u)2 : (1/w)2 + (1/u)2 - (1/v)2 : (1/u)2 + (1/v)2 - (1/w)2, where
                        u : v : w = X(21); e.g., u = u(A,B,C) = 1/(cos B + cos C)

Barycentrics  a[(1/v)2 + (1/w)2 - (1/u)2] : b[(1/w)2 + (1/u)2 - (1/v)2] : c[(1/u)2 + (1/v)2 - (1/w)2]

X(411) lies on these lines: 2,3   35,516   40,78   55,962   81,581   165,936   185,970   243,821   255,651


X(412)

Trilinears       (1/v)2 + (1/w)2 - (1/u)2 : (1/w)2 + (1/u)2 - (1/v)2 : (1/u)2 + (1/v)2 - (1/w)2, where
                        u : v : w = X(29); e.g., u = u(A,B,C) = (sec A)/(cos B + cos C)

Barycentrics  a[(1/v)2 + (1/w)2 - (1/u)2] : b[(1/w)2 + (1/u)2 - (1/v)2] : c[(1/u)2 + (1/v)2 - (1/w)2]

X(412) lies on these lines: 2,3   40,92   46,158   63,318   65,243   162,580   225,775   278,962


X(413)

Trilinears       u3(v2 + w2 - vw) : v3(w2 + u2 - wu) : w3(u2 + v2 - uv), where
                        u : v : w = X(21); e.g., u = u(A,B,C) = 1/(cos B + cos C)

Barycentrics  au3(v2 + w2 - vw) : bv3(w2 + u2 - wu) : cw3(u2 + v2 - uv)

X(413) lies on this line: 2,3


X(414)

Trilinears       u3(v2 + w2 - vw) : v3(w2 + u2 - wu) : w3(u2 + v2 - uv), where
                        u : v : w = X(29); e.g., u = u(A,B,C) = (sec A)1/(cos B + cos C)

Barycentrics  au3(v2 + w2 - vw) : bv3(w2 + u2 - wu) : cw3(u2 + v2 - uv)

X(414) lies on this line: 2,3


X(415)

Trilinears       (u2 - vw)sec A : (v2 - wu)sec B : (v2 - uv)sec C, where
                        u : v : w = X(21); e.g., u = u(A,B,C) = 1/(cos B + cos C)

Barycentrics  (u2 - vw)tan A : (v2 - wu)tan B : (w2 - uv)tan C

X(415) lies on these lines: 2,3   162,238

X(415) = X(4)-Hirst inverse of X(29)


X(416)

Trilinears       (u2 - vw)sec A : (v2 - wu)sec B : (v2 - uv)sec C, where
                        u : v : w = X(29); e.g., u = u(A,B,C) = (sec A)/(cos B + cos C)

Barycentrics  (u2 - vw)tan A : (v2 - wu)tan B : (w2 - uv)tan C

X(416) lies on this line: 2,3

X(416) = X(3)-Hirst inverse of X(21)


X(417)

Trilinears       f(A,B,C) : f(B,C,A) : f(C,A,B), where f(A,B,C) = (cos A)(sec2B + sec2C)
Barycentrics  g(A,B,C) : g(B,C,A) : g(C,A,B), where g(A,B,C) = (sin 2A)(sec2B + sec2C)

X(417) lies on this line: 2,3

X(417) = X(3)-Ceva conjugate of X(185)


X(418)

Trilinears       f(A,B,C) : f(B,C,A) : f(C,A,B), where f(A,B,C) = (cos A)(csc 2B + csc 2C)
Barycentrics  g(A,B,C) : g(B,C,A) : g(C,A,B), where g(A,B,C) = (sin 2A)(csc 2B + csc 2C)

X(418) lies on these lines: 2,3   51,216   97,110   154,160   157,161   184,577

X(418) = X(I)-Ceva conjugate of X(J) for these (I,J): (3,216), (216,217)


X(419)

Trilinears       (u2 - vw)sec A : (v2 - wu)sec B : (v2 - uv)sec C, where
                        u : v : w = X(31); e.g., u = u(A,B,C) = a2

Barycentrics  (u2 - vw)tan A : (v2 - wu)tan B : (w2 - uv)tan C

X(419) lies on these lines: 2,3   238,242

X(419) = X(4)-Hirst inverse of X(25)


X(420)

Trilinears       (u2 - vw)sec A : (v2 - wu)sec B : (v2 - uv)sec C, where
                        u : v : w = X(38); e.g., u = u(a,b,c) = b2 + c2

Barycentrics  (u2 - vw)tan A : (v2 - wu)tan B : (w2 - uv)tan C

X(420) lies on this line: 2,3

X(420) = X(4)-Hirst inverse of X(427)


X(421)

Trilinears       (u2 - vw)sec A : (v2 - wu)sec B : (v2 - uv)sec C, where
                        u : v : w = X(47); e.g., u = u(A,B,C) = cos 2A

Barycentrics  (u2 - vw)tan A : (v2 - wu)tan B : (w2 - uv)tan C

X(421) lies on this line: 2,3

X(421) = X(4)-Hirst inverse of X(24)


X(422)

Trilinears       (u2 - vw)sec A : (v2 - wu)sec B : (v2 - uv)sec C, where
                        u : v : w = X(58); e.g., u = u(a,b,c) = a/(b + c)

Barycentrics  (u2 - vw)tan A : (v2 - wu)tan B : (w2 - uv)tan C

X(422) lies on these lines: 2,3   162,242

X(422) = X(4)-Hirst inverse of X(28)


X(423)

Trilinears       (u2 - vw)sec A : (v2 - wu)sec B : (v2 - uv)sec C, where
                        u : v : w = X(81); e.g., u = u(a,b,c) = 1/(b + c)

Barycentrics  (u2 - vw)tan A : (v2 - wu)tan B : (w2 - uv)tan C

X(423) lies on this line: 2,3

X(423) = X(4)-Hirst inverse of X(27)


X(424)

Trilinears       (u2 - vw)sec A : (v2 - wu)sec B : (v2 - uv)sec C, where
                        u : v : w = X(191); e.g., u = u(a,b,c) = (b + c - a)(bc + ca + ab) + b3 + c3 - a3

Barycentrics  (u2 - vw)tan A : (v2 - wu)tan B : (w2 - uv)tan C

X(424) lies on this line: 2,3

X(424) = X(4)-Hirst inverse of X(451)


X(425)

Trilinears       (u2 - vw)sec A : (v2 - wu)sec B : (v2 - uv)sec C, where
                        u : v : w = X(283); e.g., u = u(A,B,C) = (cos A)/(cos B + cos C)

Barycentrics  (u2 - vw)tan A : (v2 - wu)tan B : (w2 - uv)tan C

X(425) lies on this line: 2,3   243,662

X(425) = X(4)-Hirst inverse of X(21)


X(426)

Trilinears       (v2 + w2)cos A : (w2 + u2)cos B : (u2 + v2)cos C, where
                        u : v : w = X(19); e.g., u = u(A,B,C) = tan A

Barycentrics  (v2 + w2)sin 2A : (w2 + u2)sin 2B : (u2 + v2)sin 2C

X(426) lies on this line: 2,3


X(427)

Trilinears       (v + w)sec A : (w + u)sec B : (u + v)sec C, where
                        u : v : w = X(31); e.g., u = u(a,b,c) = a2

Barycentrics  (v + w)tan A : (w + u)tan B : (u + v)tan C

X(427) lies on these lines:
2,3   6,66   11,33   12,34   51,125   53,232   98,275   112,251   114,136   183,317   230,571   264,305   343,511

X(427) = midpoint between X(4) and X(378)
X(427) = inverse of X(468) in the nine-point circle
X(427) = inverse of X(25) in the orthocentroidal circle
X(427) = complement of X(22)
X(427) = X(112)-Ceva conjugate of X(523)
X(427) = X(39)-cross conjugate of X(141)
X(427) = crosspoint of X(4) and X(264)
X(427) = X(4)-Hirst inverse of X(429)


X(428)

Trilinears       (v + w)sec A : (w + u)sec B : (u + v)sec C, where
                        u : v : w = X(38); e.g., u = u(a,b,c) = b2 + c2

Barycentrics  (v + w)tan A : (w + u)tan B : (u + v)tan C

X(428) lies on these lines: 2,3   132,137


X(429)

Trilinears       (v + w)sec A : (w + u)sec B : (u + v)sec C, where
                        u : v : w = X(58); e.g., u = u(a,b,c) = a/(b + c)

Barycentrics  (v + w)tan A : (w + u)tan B : (u + v)tan C

X(429) lies on these lines: 2,3   11,1104   12,37   108,961   119,136   495,1068

X(429) = X(108)-Ceva conjugate of X(523)


X(430)

Trilinears       (v + w)sec A : (w + u)sec B : (u + v)sec C, where
                        u : v : w = X(81); e.g., u = u(a,b,c) = 1/(b + c)

Barycentrics  (v + w)tan A : (w + u)tan B : (u + v)tan C

X(430) lies on these lines: 2,3   118,136   210,594


X(431)

Trilinears       (v + w)sec A : (w + u)sec B : (u + v)sec C, where
                        u : v : w = X(283); e.g., u = u(A,B,C) = (cos A)/(cos B + cos C)

Barycentrics  (v + w)tan A : (w + u)tan B : (u + v)tan C

X(431) lies on these lines: 2,3   119,135


X(432)

Trilinears       (v2 + w2)sec A : (w2 + u2)sec B : (u2 + v2)sec C, where
                        u : v : w = X(155); e.g., u = u(A,B,C) = (cos A)(cos2B + cos2C - cos2A)

Barycentrics  (v2 + w2)tan A : (w2 + u2)tan B : (u2 + v2)tan C

X(432) lies on this line: 2,3


X(433)

Trilinears       (v2 + w2)sec A : (w2 + u2)sec B : (u2 + v2)sec C, where u : v : w = X(159)
Barycentrics  (v2 + w2)tan A : (w2 + u2)tan B : (u2 + v2)tan C

X(433) lies on this line: 2,3


X(434)

Trilinears       (v2 + w2)sec A : (w2 + u2)sec B : (u2 + v2)sec C, where u : v : w = X(195)
Barycentrics  (v2 + w2)tan A : (w2 + u2)tan B : (u2 + v2)tan C

X(434) lies on this line: 2,3


X(435)

Trilinears       (v2 + w2)sec A : (w2 + u2)sec B : (u2 + v2)sec C, where u : v : w = X(399)
Barycentrics  (v2 + w2)tan A : (w2 + u2)tan B : (u2 + v2)tan C

X(435) lies on this line: 2,3


X(436)

Trilinears       (u2 + vw)sec A : (v2 + wu)sec B : (w2 + uv)sec C, where
                        u : v : w = X(48); e.g., u(A,B,C) = sin 2A

Barycentrics  (u2 + vw)tan A : (v2 + wu)tan B : (w2 + uv)tan C

X(436) lies on these lines: 2,3   51,107   110,324   578,1093


X(437)

Trilinears       (u2 + vw)sec A : (v2 + wu)sec B : (w2 + uv)sec C, where u : v : w = X(214)
Barycentrics  (u2 + vw)tan A : (v2 + wu)tan B : (w2 + uv)tan C

X(437) lies on this line: 2,3


X(438)

Trilinears       (u2 + vw)csc A : (v2 + wu)csc B : (w2 + uv)csc C, where
                        u : v : w = X(204); e.g., u(A,B,C) = (tan A)(tan B + tan C - tan A)

Barycentrics  u2 + vw : v2 + wu : w2 + uv

X(438) lies on this line: 2,3


X(439)

Trilinears       au2 : bv2 : cw2, where
                        u : v : w = X(193); e.g., u(A,B,C) = (csc A)(cot B + cot C - cot A)

Barycentrics  (au)2 : (bv)2 : (cw)2

X(439) lies on this line: 2,3

X(439) = X(459)-Ceva conjugate of X(193)


X(440)

Trilinears       bc(v + w) : ca(w + u) : ab(u + v), where
                        u : v : w = X(28); e.g., u(a,b,c) = (tan A)/(b + c)

Barycentrics  v + w : w + u : u + v

X(440) lies on these lines: 2,3   37,226   72,306   118,122   950,1104

X(440) = complement of X(27)
X(440) = X(190)-Ceva conjugate of X(525)
X(440) = crosspoint of X(2) and X(306)


X(441)

Trilinears       bc(v + w) : ca(w + u) : ab(u + v), where
                        u : v : w = X(240); e.g., u(A,B,C) = sec A cos(A + ω)

Barycentrics  v + w : w + u : u + v

X(441) lies on these lines: 2,3   141,577   525,647

X(441) = complement of X(297)


X(442)  COMPLEMENT OF SCHIFFLER POINT

Trilinears       bc(v + w) : ca(w + u) : ab(u + v), where
                        u : v : w = X(284); e.g., u(A,B,C) = (sin A)/(cos B + cos C)

Barycentrics  v + w : w + u : u + v

X(442) lies on these lines: 2,3   8,495   9,46   10,12   11,214   100,943   115,120   119,125   274,325   388,956   392,946

X(442) = midpoint between X(79) and X(191)
X(442) = inverse of X(405) in the orthocentroidal circle
X(442) = complement of X(21)
X(442) = X(100)-Ceva conjugate of X(523)
X(442) = crosspoint of X(264) and X(321)


X(443)

Trilinears       bc(v + w) : ca(w + u) : ab(u + v), where
                        u : v : w = X(380)

Barycentrics  v + w : w + u : u + v

X(443) lies on these lines: 1,142   2,3   7,72   8,942   10,57   69,274   226,936   278,1038   387,940   392,962   579,966

X(443) = complement of X(452)


X(444)

Trilinears       (v + w)tan A : (w + u)tan B : (u + v)tan C, where
                        u : v : w = X(256); e.g., u(a,b,c) = 1/(a2 + bc)

Barycentrics  (v + w)(sin A tan A) : (w + u)(sin B tan B) : (u + v)(sin C tan C)

X(444) lies on these lines: 2,3   19,232


X(445)

Trilinears       (v + w)csc 2A : (w + u)csc 2B : (u + v)csc 2C, where
                        u : v : w = X(79); e.g., u(a,b,c) = 1/(1 + 2 cos A)

Barycentrics  (v + w)sec A : (w + u)sec B : (u + v)sec C

X(445) lies on this line: 2,3


X(446)

Trilinears       u(v2 + w2) : v(w2 + u2) : w(u2 + v2), where
                        u : v : w = X(98); e.g., u(A,B,C) = sec(A + ω)

Barycentrics  au(v2 + w2) : bv(w2 + u2) : cw(u2 + v2)

X(446) lies on this line: 2,3

X(446) = crosspoint of X(98) and X(511)


X(447)

Trilinears       bc(u2 - vw) : ca(v2 - wu) : ab(w2 - uv), where
                        u : v : w = X(28); e.g., u(a,b,c) = (tan A)/(b + c)

Barycentrics  u2 - vw : v2 - wu : w2 - uv

X(447) lies on this line: 2,3   340,540   350,811   519,648

X(447) = X(2)-Hirst inverse of X(27)


X(448)

Trilinears       bc(u2 - vw) : ca(v2 - wu) : ab(w2 - uv), where
                        u : v : w = X(284); e.g., u(A,B,C) = (sin A)/(cos B + cos C)

Barycentrics  u2 - vw : v2 - wu : w2 - uv

X(448) lies on this line: 2,3

X(448) = X(2)-Hirst inverse of X(21)


X(449)

Trilinears       bc(u2 - vw) : ca(v2 - wu) : ab(w2 - uv), where u : v : w = X(380)
Barycentrics  u2 - vw : v2 - wu : w2 - uv

X(449) lies on this line: 2,3

X(449) = X(2)-Hirst inverse of X(452)


X(450)  X(3)-HIRST INVERSE OF X(4)

Trilinears       f(A,B,C) : f(B,C,A) : f(C,A,B), where f(A,B,C) = (sec A)[cos4A - (cos B cos C)2]
                        = g(A,B,C) : g(B,C,A) : g(C,A,B), where g(A,B,C) = (cos A)[sec4A - (sec B sec C)2]

Barycentrics  h(A,B,C) : h(B,C,A) : h(C,A,B), where h(A,B,C) = (tan A)(cos4A - (cos B cos C)2]

X(450) lies on these lines: 2,3   107,511   155,1075   1092,1093

X(450) = X(3)-Hirst inverse of X(4)


X(451)

Trilinears       u sec A : v sec B : w sec C, where u : v : w = X(191)
Barycentrics  u tan A : v tan B : w tan C

X(451) lies on these lines: 2,3   12,108   281,1068

X(451) = X(4)-Hirst inverse of X(424)


X(452)

Trilinears       u csc A : v csc B : w csc C, where u : v : w = X(380)
Barycentrics  u : v : w

X(452) lies on these lines: 1,329   2,3   8,9   34,347   63,938   72,145   388,1001   392,944   497,958   956,1058

X(452) = anticomplement of X(443)
X(452) = X(2)-Hirst inverse of X(449)


X(453)

Trilinears       u2/(cos B + cos C) : v2/(cos C + cos A) : w2/(cos A + cos B), where u : v : w = X(46)
Barycentrics  (u2sin A)/(cos B + cos C) : (v2sin B)/(cos C + cos A) : (w2sin C)/(cos A + cos B)

X(453) lies on this line: 2,3


X(454)

Trilinears       u2sec A : v2sec B : w2sec C, where
                        u : v : w = X(155); e.g., u(A,B,C) = (cos A)[cos2B + cos2C - cos2A]

Barycentrics  u2tan A : v2tan B : w2tan C

X(454) lies on this line: 2,3


X(455)

Trilinears       u2sec A : v2sec B : w2sec C, where u : v : w = X(159)
Barycentrics  u2tan A : v2tan B : w2tan C

X(455) lies on this line: 2,3


X(456)

Trilinears       u2sec A : v2sec B : w2sec C, where u : v : w = X(195)
Barycentrics  u2tan A : v2tan B : w2tan C

X(456) lies on this line: 2,3


X(457)

Trilinears       u2sec A : v2sec B : w2sec C, where u : v : w = X(399)
Barycentrics  u2tan A : v2tan B : w2tan C

X(457) lies on this line: 2,3


X(458)

Trilinears       u csc 2A : v csc 2B : w csc 2C, where
                        u : v : w = X(182); e.g.; u(A,B,C) = cos(A - ω)

Barycentrics  u sec A : v sec B : w sec C

X(458) lies on these lines: 2,3   6,264   76,275   141,317   239,318   273,894   315,343   340,599

X(458) = inverse of X(297) in the orthocentroidal circle


X(459)

Trilinears       u tan A : v tan B : w tan C, where
                        u : v : w = X(193); e.g.; u(A,B,C) = (csc A)(cot B + cot C - cot A)

Barycentrics  u sin A tan A : v sin B tan B : w sin C tan C

X(459) lies on these lines: 2,3   230,393   232,800   242,278   317,1007

X(459) = cevapoint of X(193) and X(439)
X(459) = X(393)-cross conjugate of X(4)
X(459) = X(4)-Hirst inverse of X(460)


X(460)

Trilinears       u tan A : v tan B : w tan C, where u : v : w = X(230)
Barycentrics  u sin A tan A : v sin B tan B : w sin C tan C

X(460) lies on this line: 2,3

X(460) = X(4)-Hirst inverse of X(459)


X(461)

Trilinears       u tan A : v tan B : w tan C, where
                        u : v : w = X(391); e.g., u(a,b,c) = bc(3a + b + c)(b + c - a)

Barycentrics  u sin A tan A : v sin B tan B : w sin C tan C

X(461) lies on these lines: 2,3   33,200


X(462)

Trilinears       u tan A : v tan B : w tan C, where
                        u : v : w = X(395); e.g., u(A,B,C) = cos(B - C) + 2 cos(A + π/3)

Barycentrics  u sin A tan A : v sin B tan B : w sin C tan C

X(462) lies on these lines: 2,3   51,397   184,398  


X(463)

Trilinears       u tan A : v tan B : w tan C, where
                        u : v : w = X(396); e.g., u(A,B,C) = cos(B - C) + 2 cos(A - π/3)

Barycentrics  u sin A tan A : v sin B tan B : w sin C tan C

X(463) lies on these lines: 2,3   51,398   184,397


X(464)

Trilinears       u cot A : v cot B : w cot C, where u : v : w = X(387)
Barycentrics  u cos A : v cos B : w cos C

X(464) lies on these lines: 2,3   63,69


X(465)

Trilinears       u cot A : v cot B : w cot C, where
                        u : v : w = X(397); e.g., u(A,B,C) = cos(B - C) - 2 cos(A + π/3)

Barycentrics  u cos A : v cos B : w cos C

X(465) lies on these lines: 2,3   216,395   396,577

X(465) = complement of X(473)


X(466)

Trilinears       u cot A : v cot B : w cot C, where
                        u : v : w = X(398); e.g., u(A,B,C) = cos(B - C) - 2 cos(A - π/3)

Barycentrics  u cos A : v cos B : w cos C

X(466) lies on these lines: 2,3   216,396   395,577

X(446) = complement of X(472)


X(467)

Trilinears       u csc 2A : v csc 2B : w csc 2C, where
                        u : v : w = X(52); e.g., u(A,B,C) = cos 2A cos(B - C)

Barycentrics  u sec A : v sec B : w sec C

X(467) lies on these lines: 2,3   53,311

X(467) = X(317)-Ceva conjugate of X(52)


X(468)  X(2)-LINE CONJUGATE OF X(3)

Trilinears       u csc 2A : v csc 2B : w csc 2C, where
                        u : v : w = X(187); e.g., u(a,b,c) = a(2a2 - b2 - c2)

Barycentrics  u sec A : v sec B : w sec C

X(468) lies on these lines: 2,3   98,685   107,842   111,935   230,231   250,325

X(468) = midpoint between X(186) and X(403)
X(468) = isogonal conjugate of X(895)
X(468) = inverse of X(25) in the circumcircle
X(468) = inverse of X(427) in the nine-point circle
X(468) = X(187)-cross conjugate of X(524)
X(468) = X(2)-line conjugate of X(3)

Let X = X(468) and let V be the vector-sum XA + XB + XC; then V = X(468)X(23).


X(469)

Trilinears       u csc 2A : v csc 2B : w csc 2C, where
                        u : v : w = X(386); e.g., u(a,b,c) = a(b2 + c2 + bc + ca + ab)

Barycentrics  u sec A : v sec B : w sec C

X(469) lies on these lines: 2,3   92,264   226,273

X(469) = inverse of X(27) in the orthocentroidal circle


X(470)

Trilinears       sin(A + π/3) csc 2A : sin(B + π/3) csc 2B : sin(C + π/3) csc 2C
Barycentrics  sin(A + π/3) sec A : sin(B + π/3) sec B : sin(C + π/3) sec 2C

X(470) lies on these lines: 2,3   18,275   264,301   298,340   302,317   343,634   394,633

X(470) = inverse of X(471) in the orthocentroidal circle
X(470) = X(15)-cross conjugate of X(298)
X(470) = X(4)-Hirst inverse of X(471)


X(471)

Trilinears       sin(A - π/3) csc 2A : sin(B - π/3) csc 2B : sin(C - π/3) csc 2C
Barycentrics  sin(A - π/3) sec A : sin(B - π/3) sec B : sin(C - π/3) sec 2C

X(471) lies on these lines: 2,3   17,275   264,300   299,340   303,317   343,633   394,634

X(471) = inverse of X(470) in the orthocentroidal circle
X(471) = X(16)-cross conjugate of X(299) for these (I,J): (71,10), (72,307), (440,2)
X(471) = X(4)-Hirst inverse of X(470)


X(472)

Trilinears       cos(A + π/3) csc 2A : cos(B + π/3) csc 2B : cos(C + π/3) csc 2C
Barycentrics  cos(A + π/3) sec A : cos(B + π/3) sec B : cos(C + π/3) sec 2C

X(472) lies on these lines: 2,3   13,275   53,395   264,298   299,317   343,621   394,622

X(472) = inverse of X(473) in the orthocentroidal circle
X(472) = anticomplement of X(466)
X(472) = X(62)-cross conjugate of X(303)


X(473)

Trilinears       cos(A - π/3) csc 2A : cos(B - π/3) csc 2B : cos(C - π/3) csc 2C
Barycentrics  cos(A - π/3) sec A : cos(B - π/3) sec B : cos(C - π/3) sec 2C

X(473) lies on these lines: 2,3   14,275   53,396   264,299   298,317   343,622   394,621

X(473) = inverse of X(472) in the orthocentroidal circle
X(473) = anticomplement of X(465)
X(473) = X(61)-cross conjugate of X(302)


X(474)

Trilinears       cos A - (a + b + c)/a : cos B - (a + b + c)/b : cos C - (a + b + c)/c
Barycentrics  a cos A - (a + b + c) : b cos B - (a + b + c) : c cos C - (a + b + c)

X(474) lies on these lines: 2,3   8,999   10,56   35,1001   36,958   40,392   46,960   57,72   65,997   78,942   142,954   171,978   183,274   244,976   283,582   386,940   579,965   986,1054


X(475)

Trilinears       sec A - (a + b + c)/a : sec B - (a + b + c)/b : sec C - (a + b + c)/c
Barycentrics  a sec A - (a + b + c) : b sec B - (a + b + c) : c sec C - (a + b + c)

X(475) lies on these lines: 2,3   8,1063   10,34   264,274   318,1068

X(475) = inverse of X(406) in the orthocentroidal circle


X(476) = TIXIER POINT

Trilinears       f(A,B,C) : f(B,C,A) : f(C,A,B), where f(A,B,C) = 1/[(1 + 2 cos 2A)(sin(B - C)]
Barycentrics  (sin A)f(A,B,C) : (sin B)f(B,C,A) : (sin C)f(C,A,B)

The reflection of X(110) about the Euler line; X(476) lies on the circumcircle. (Michel Tixier, 5/9/98). Also, X(476) is the center of the polar conic of X(30) with respect to the Neuberg cubic; this conic is a rectangular hyperbola passing through the incenter, the excenters, and X(30). (Peter Yff, 5/23/99)

X(476) lies on these lines: 2,842   3,477   23,94   30,74   99,850   110,523   111,230   250,933   376,841

X(476) = reflection of X(477) about X(3)
X(476) = isogonal conjugate of X(526)
X(476) = cevapoint of X(30) and X(523)


X(477) = TIXIER ANTIPODE

Trilinears       f(A,B,C) : f(B,C,A) : f(C,A,B), where f(A,B,C) = 1/[4 cos A + cos(A - 2B) + cos(A - 2C) - 3 cos(B - C)]
Barycentrics  (sin A)f(A,B,C) : (sin B)f(B,C,A) : (sin C)f(C,A,B)

The reflection of X(476) about X(3), on the circumcircle. (Michel Tixier, 5/16/98)

X(477) lies on these lines: 3,476   30,110   50,112   74,523   107,186   376,691   378,935

X(477) = reflection of X(476) about X(3)


X(478) = CENTER OF YIU CONIC

Trilinears       f(a,b,c) : f(b,c,a) : f(c,a,b), where f(a,b,c) = a[a4 - 2abc(b + c - a) - (b2 - c2)2]/(b + c - a)
Barycentrics  h(a,b,c) : h(b,c,a) : h(c,a,b), where h(a,b,c) = af(a,b,c)

Center of the Yiu conic, which passes through the points outside the circumcircle at which the excircles of ABC are tangent to the sidelines of ABC. (PaulYiu, "The Clawson point and excircles," 1999)

X(478) lies on these lines: 6,19   9,1038   69,651   109,573   198,577   222,226


X(479)

Trilinears       (tan A/2 sec A/2)2 : (tan B/2 sec B/2)2 : (tan C/2 sec C/2)2

Barycentrics  tan3(A/2) : tan3(B/2) : tan3(C/2)
                        = 1/(b + c - a)3 : 1/(c + a - b)3 : 1/(a + b - c)3

Let A' be the point in which the incircle is tangent to a circle that passes through vertices B and C, and determine B' and C' cyclically. The lines AA', BB', CC' concur in X(479)

Clark Kimberling and Peter Yff, Problem 10678, American Mathematical Monthly 105 (1998) 666.

X(479) lies on these lines: 7,354   57,279   269,614

X(479) = isogonal conjugate of X(480)
X(479) = X(269)-cross conjugate of X(279)


X(480)

Trilinears       (cot A/2 cos A/2)2 : (cot B/2 cos B/2)2 : (cot C/2 cos C/2)2
Barycentrics  (sin A)(cot A/2 cos A/2)2 : (sin B)(cot B/2 cos B/2)2 : (sin C)(cot C/2 cos C/2)2

The radical center of the three circles used to construct X(479). (Peter Yff, 5/6/98)

X(480) lies on these lines: 8,344   9,55   10,954   56,78   100,144

X(480) = isogonal conjugate of X(479)
X(480) = X(200)-Ceva conjugate of X(220)


X(481) = 1st EPPSTEIN POINT

Trilinears       f(A,B,C) : f(B,C,A) : f(C,A,B), where f(A,B,C) = 1 - 2 sec A/2 cos B/2 cos C/2
                        = 1 - 4(area)/[a(b + c - a)] : 1 - 4(area)/[b(c + a - b)] : 1 - 4(area)/[c(a + b - c) [E. Brisse, 3/20/01]
Barycentrics  (sin A)f(A,B,C) : (sin B)f(B,C,A) : (sin C)f(C,A,B).

Let S be the inner Soddy circle and Sa, Sb, Sc the Soddy circles tangent to S. Let Ia = S^Sa, Ea = Sb^Sc, and determine Ib, Ic, Eb, Ec cyclically. Then X(481) is the point of concurrence of lines Ia-to-Ea, Ib-to-Eb, Ic-to-Ec.

David Eppstein, "Tangent spheres and triangle centers," American Mathematical Monthly, 108 (2001) 63-66.

X(481) lies on these lines: 1,7   226,485

X(481) = X(79)-Ceva conjugate of X(482)


X(482) = 2nd EPPSTEIN POINT

Trilinears       f(A,B,C) : f(B,C,A) : f(C,A,B), where f(A,B,C) = 1 + 2 sec A/2 cos B/2 cos C/2
                        = 1 + 4(area)/[a(b + c - a)] : 1 + 4(area)/[b(c + a - b)] : 1 + 4(area)/[c(a + b - c) [E. Brisse, 3/20/01]
Barycentrics  (sin A)f(A,B,C) : (sin B)f(B,C,A) : (sin C)f(C,A,B).

Let S' be the outer Soddy circle and Sa, Sb, Sc the Soddy circles tangent to S. Let Ja = S'^Sa, Ea = Sb^Sc, and determine Jb, Jc, Eb, Ec cyclically. Then X(482) is the point of concurrence of lines Ja-to-Ea, Jb-to-Eb, Jc-to-Ec.

David Eppstein, "Tangent spheres and triangle centers," American Mathematical Monthly, 108 (2001) 63-66.

X(482) lies on these lines: 1,7   226,486

X(482) = X(79)-Ceva conjugate of X(481)


X(483) = RADICAL CENTER OF AJIMA-MALFATTI CIRCLES

Trilinears       sec2A/4 : sec2B/4 : sec2C/4
                        = 1/(1 + cos A/2) : 1/(1 + cos B/2) : 1/(1 + cos C/2)

Barycentrics  sin A sec2A/4 : sin B sec2B/4 : sin C sec2C/4

The Ajima-Malfatti circles are described at X(179). (Peter Yff, 6/1/98)

X(483) lies on these lines: 8,178   173,180   174,175


X(484) = EVANS PERSPECTOR

Trilinears       1 + 2(cos A - cos B - cos C) : 1 + 2(cos B - cos C - cos A) : 1 + 2(cos C + cos A - cos B)
Barycentrics  a[1 + 2(cos A - cos B - cos C)] : b[1 + 2(cos B - cos C - cos A)] : c[1 + 2(cos C + cos A - cos B)]

X(484) is the perspector of the extriangle and the triangle A'B'C', where A' is the reflection of vertex A about sideline BC and B', C' are determined cyclically. (Lawrence Evans, 10/22/98)

X(484) lies on these lines: 1,3   10,191   12,79   30,80   63,535   100,758   499,962   759,901   1046,1048

X(484) = reflection of X(1) about X(36)
X(484) = inverse of X(35) in the circumcircle
X(484) = X(80)-Ceva conjugate of X(1)



leftri Centers 485- 495, rightri
371, and 372: Vierkanten in een driehoek - triangle centers associated with squares.

underbar

X(485) = VECTEN POINT

Trilinears       sec(A - π/4) : sec(B - π/4) : sec(C - π/4)
Barycentrics  sin A sec(A - π/4) : sin B sec(B - π/4) : sin C sec(C - π/4)

X(485) is the perspector of triangles associated with squares that circumscribe ABC. For details, visit Floor van Lamoen's site, Vierkanten in een driehoek: 1. Omgeschreven vierkanten (van Lamoen, 4/26/98) and his article "Friendship Among Triangle Centers," Forum Geometricorum, 1 (2001) 1-6.

X(485) lies on these lines: 2,372   3,590   4,371   5,6   69,639   76,491   226,481   489,671

X(485) = isogonal conjugate of X(371)
X(485) = isotomic conjugate of X(492)
X(485) = complement of X(488)
X(485) = anticomplement of X(641)
X(485) = X(3)-cross conjugate of X(486)


X(486) = INNER VECTEN POINT

Trilinears       sec(A + π/4) : sec(B + π/4) : sec(C + π/4)
Barycentrics  sin A sec(A + π/4) : sin B sec(B + π/4) : sin C sec(C + π/4)

X(486) is a perspector of triangles associated with squares that circumscribe ABC. For details and references, see X(485). (Floor van Lamoen, 4/26/98)

X(486) lies on these lines: 2,371   3,615   4,372   5,6   76,492   141,591   226,482   490,671

X(486) = isogonal conjugate of X(372)
X(486) = isotomic conjugate of X(491)
X(486) = complement of X(487)
X(485) = anticomplement of X(642)
X(486) = X(3)-cross conjugate of X(485)


X(487)

Trilinears       f(A,B,C) : f(B,C,A) : f(C,A,B), where f(A,B,C) = (cos A)(1 - csc A sin B sin C)
Barycentrics  (sin A)f(A,B,C) : (sin B)f(B,C,A) : (sin C)f(C,A,B)

X(487) is a perspector of triangles associated with squares that circumscribe ABC. (Floor van Lamoen, 4/29/98)

X(487) lies on these lines: 2,371   3,69   4,489   20,638   193,372   376,490   492,631

X(487) = anticomplement of X(486)
X(487) = X(I)-Ceva conjugate of X(J) for these (I,J): (4,488), (489,20), (491,2)


X(488)

Trilinears       f(A,B,C) : f(B,C,A) : f(C,A,B), where f(A,B,C) = (cos A)(1 + csc A sin B sin C)
Barycentrics  (sin A)f(A,B,C) : (sin B)f(B,C,A) : (sin C)f(C,A,B)

X(488) is a perspector of triangles associated with squares that circumscribe ABC. For details, see Vierkanten in een driehoek: 2. Meer punten uit omgeschreven vierkanten (Floor van Lamoen, 4/29/98)

X(488) lies on these lines: 2,372   3,69   4,490   193,371   376,489   491,631

X(488) = anticomplement of X(485)
X(488) = X(I)-Ceva conjugate of X(J), for these (I,J): (4,487), (490,20), (492,2)


X(489)

Trilinears       f(A,B,C) : f(B,C,A) : f(C,A,B), where f(A,B,C) = (cos A)(1 - csc A sin B sin C) - cos B cos C
Barycentrics  (sin A)f(A,B,C) : (sin B)f(B,C,A) : (sin C)f(C,A,B)

X(489) is a perspector of triangles associated with squares that circumscribe ABC. For details and reference, see X(488). (Floor van Lamoen, 4/29/98)

X(489) lies on these lines: 3,492   4,487   20,64   30,638   176,664   376,488   485,671

X(489) = cevapoint of X(20) and X(487)


X(490)

Trilinears       f(A,B,C) : f(B,C,A) : f(C,A,B), where f(A,B,C) = (cos A)(1 + csc A sin B sin C) - cos B cos C
Barycentrics  (sin A)f(A,B,C) : (sin B)f(B,C,A) : (sin C)f(C,A,B)

X(490) is a perspector of triangles associated with squares that circumscribe ABC. For details and reference, see X(488). (Floor van Lamoen, 4/29/98)

X(490) lies on these lines: 3,491   4,488   20,64   30,637   175,664   376,487   486,671

X(490) = cevapoint of X(20) and X(488)


X(491)

Trilinears       f(A,B,C) : f(B,C,A) : f(C,A,B), where f(A,B,C) = (cos A)(1 - csc A sin B sin C) + cos B cos C
Barycentrics  (sin A)f(A,B,C) : (sin B)f(B,C,A) : (sin C)f(C,A,B)

X(491) is a pole associated with squares that circumscribe ABC. For details and reference, see X(488). (Floor van Lamoen, 4/26/98)

X(491) lies on these lines: 2,6   3,490   4,487   5,637   76,485   315,371   372,642   488,631

X(491) = isotomic conjugate of X(486)
X(491) = anticomplement of X(615)
X(491) = X(264)-Ceva conjugate of X(492)
X(491) = cevapoint of X(2) and X(487)


X(492)

Trilinears       f(A,B,C) : f(B,C,A) : f(C,A,B), where f(A,B,C) = (cos A)(1 + csc A sin B sin C) + cos B cos C
Barycentrics  (sin A)f(A,B,C) : (sin B)f(B,C,A) : (sin C)f(C,A,B)

X(492) is a pole associated with squares that circumscribe ABC. For details and reference, see X(488). (Floor van Lamoen, 4/27/98)

X(492) lies on these lines: 2,6   3,489   4,488   5,638   76,486   315,372   371,641   487,631

X(492) = isotomic conjugate of X(485)
X(492) = anticomplement of X(590)
X(492) = X(264)-Ceva conjugate of X(491)
X(492) = cevapoint of X(2) and X(488)


X(493)

Trilinears       f(A,B,C) : f(B,C,A) : f(C,A,B), where f(A,B,C) = 1/(sin A + sin B sin C)
Barycentrics  (sin A)f(A,B,C) : (sin B)f(B,C,A) : (sin C)f(C,A,B)

X(493) is a homothetic center of triangles associated with squares that circumscribe ABC. For details, see Vierkanten in een driehoek: 4. Ingeschreven vierkanten (Floor van Lamoen, 4/27/98)

X(493) lies on these lines: 25,371   39,494

X(493) = X(394)-cross conjugate of X(494)


X(494)

Trilinears       f(A,B,C) : f(B,C,A) : f(C,A,B), where f(A,B,C) = 1/(sin A - sin B sin C)
Barycentrics  (sin A)f(A,B,C) : (sin B)f(B,C,A) : (sin C)f(C,A,B)

X(494) is a homothetic center of triangles associated with squares that circumscribe ABC. For details and reference, see X(393). (Floor van Lamoen, 4/27/98)

X(494) lies on these lines: 25,372   39,493

X(494) = X(394)-cross conjugate of X(493)


X(495) = JOHNSON MIDPOINT

Trilinears       2 + cos(B - C) : 2 + cos(C - A) : 2 + cos(A - B)
Barycentrics  (sin A)[2 + cos(B - C)] : (sin B)[2 + cos(C - A)] : (sin C)[2 + cos(A - B)]

X(495) is the midpoint of segments C1-to-P1, C2-to-P2, C3-to-P3 in the Johnson four-circle configuration.

Roger A. Johnson, Advanced Euclidean Geometry, Dover, New York, 1960, page 75.

Peter Yff, "Three concurrent congruent circles 'inscribed' in a triangle," manuscript, 1998; X(495) is the point R on page 5.

X(495) lies on these lines:
1,5   2,956   3,388   4,390   8,442   10,141   30,55   35,550   36,549   56,140   202,395   203,396   226,517   381,497   392,908   429,1068   529,993   612,1060

X(495) = complement of X(956)


X(496) = HARMONIC CONJUGATE OF X(495) WRT X(1) AND X(5)

Trilinears       2 - cos(B - C) : 2 - cos(C - A) : 2 - cos(A - B)
Barycentrics  (sin A)[2 - cos(B - C)] : (sin B)[2 - cos(C - A)] : (sin C)[2 - cos(A - B)]

Peter Yff, "Three concurrent congruent circles 'inscribed' in a triangle," manuscript, 1998; X(496) is the point R' on page 5.

X(496) lies on these lines: 1,5   2,1058   3,497   4,999   30,56   35,549   36,550   55,140   149,404   202,397   203,398   381,388   390,631   613,1069   614,1062   942,946


X(497)  CROSSPOINT OF GERGONNE POINT AND NAGEL POINT

Trilinears       1 - cos B cos C : 1 - cos C cos A : 1 - cos A cos B
Barycentrics  (sin A)(1 - cos B cos C) : (sin B)(1 - cos C cos A) : (sin C)(1 - cos A cos B)

X(497) is the harmonic conjugate of X(388) with respect to X(1) and X(4)

Peter Yff, "Three concurrent congruent circles 'inscribed' in a triangle," manuscript, 1998; X(497) is the point C' on page 5.

X(497) lies on these lines:
1,4   2,11   3,496   7,354   8,210   20,56   29,1036   30,999   35,499   36,376   57,516   65,938   69,350   80,1000   212,238   329,518   381,495   452,958   614,1040   1057,1065

X(497) = isogonal conjugate of X(1037)
X(497) = crosspoint of X(I) and X(J) for these (I,J): (7,8), (29,314)


X(498)

Trilinears       1 + 2 sin B sin C : 1 + 2 sin C sin A : 1 + 2 sin A sin B
Barycentrics  (sin A)(1 + 2 sin B sin C) : (sin B)(1 + 2 sin C sin A) : (sin C)(1 + 2 sin A sin B)

X(498) and X(499) are harmonic conjugate points with respect to X(1) and X(2), in analogy with such pairs with respect to X(1), X(4) and with respect to X(1), X(5).

Peter Yff, "Three concurrent congruent circles 'inscribed' in a triangle," manuscript, 1998; X(498) is the point S on page 6.

X(498) lies on these lines: 1,2   3,12   4,35   5,55   9,920   36,388   37,91   46,226   47,171   56,140   141,611   191,329   255,750   345,1089


X(499)

Trilinears       1 - 2 sin B sin C : 1 - 2 sin C sin A : 1 - 2 sin A sin B
Barycentrics  (sin A)(1 - 2 sin B sin C) : (sin B)(1 - 2 sin C sin A) : (sin C)(1 - 2 sin A sin B)

X(499) is the harmonic conjugate of X(498) with respect to X(1) and X(2).

Peter Yff, "Three concurrent congruent circles 'inscribed' in a triangle," manuscript, 1998; X(498) is the point S' on page 6.

X(499) lies on these lines: 1,2   3,11   4,36   5,56   12,999   17,202   18,203   35,497   46,946   47,238   55,140   57,920   80,944   141,613   255,748   348,1111   484,962


X(500) = ORTHOCENTER OF THE INCENTRAL TRIANGLE

Trilinears       f(a,b,c) : f(b,c,a) : f(c,a,b), where
                        f(a,b,c) = a(b2 +c2 - a2 + bc)[2abc + (b + c)(a2 - (b - c)2)]

Barycentrics  af(a,b,c) : bf(b,c,a) : cf(c,a,b)

X(500) lies on these lines: 1,30   3,6   651,943

X(500) = inverse of X(582) in the Brocard circle
X(500) = crosspoint of X(1) and X(35)


X(501) = MIQUEL ASSOCIATE OF INCENTER

Trilinears       f(a,b,c) : f(b,c,a) : f(c,a,b), where
                        f(a,b,c) = a/[(b + c)u], u = u(a,b,c) = a3 - b3 - c3 + ba2 - ab2 + ca2 - ac2 - cb2 - bc2 - abc

Barycentrics  af(a,b,c) : bf(b,c,a) : cf(c,a,b)

Miquel's theorem states that if A', B', C' are points (other than A, B, C) on sidelines BC, CA, AB, respectively, then the circles AB'C', BC'A', CA'B' meet at a point. Suppose P is a point and A' = P^BC, B' = P^CA, C' = P^AB; the point in which the three circles is the Miquel associate of P. (Paul Yiu, 7/6/99)

X(501) lies on this line: 1,229

X(501) = isogonal conjugate of X(502)
X(501) = X(267)-Ceva conjugate of X(58)


X(502) = CYCLOCEVIAN CONJUGATE OF X(1)

Trilinears       f(a,b,c) : f(b,c,a) : f(c,a,b), where
                        f(a,b,c) = (b + c)u/a, u = u(a,b,c) = a3 - b3 - c3 + ba2 - ab2 + ca2 - ac2 - cb2 - bc2 - abc

Barycentrics  af(a,b,c) : bf(b,c,a) : cf(c,a,b)

If A', B', C' are points (other than A, B, C) on sidelines BC, CA, AB, respectively, then the circle passing through A', B', C' passes through through points A" on BC, B" on CA, C" on AB. Suppose P is a point and A' = P^BC, B' = P^CA, C' = P^AB. Then lines AA", BB", CC" concur in the cyclocevian conjugate of P, as defined in TCCT p.226. (Paul Yiu, 7/6/99)

X(502) lies on these lines: 1,2   261,319

X(502) = isogonal conjugate of X(501)
X(502) = cyclocevian conjugate of X(1)>BR> X(502) = X(191)-cross conjugate of X(10)



leftri Centers 503- 510, rightri
173, 174, 258, and 351- 364 are associated with isoscelizers. A line L perpendicular
to the line that bisects angle A is an A-isoscelizer. Let E = L∩CA and F = L∩AB;
then |AE| = |AF|. Centers defined by Peter Yff as points X of concurrence of A-, B-, and C-
isoscelizers depend on these notations:
t(X,A) = |AE|,    h(X,A) = A-altitude of AEF,    v(X,A) = |EF|.

underbar

X(503)

Trilinears       f(A,B,C) : f(B,C,A) : f(C,A,B), where f(A,B,C) = sec B/2 + sec C/2 - sec A/2
Barycentrics  af(A,B,C) : bf(B,C,A) : cf(C,A,B)

The isoscelizer equations ah(X,A) = bh(X,B) = ch(X,C) have solution X = X(503). (Peter Yff, 4/9/99)

X(503) lies on these lines: 1,167   164,361   173,844

X(503) = X(259)-Ceva conjugate of X(1)


X(504)

Trilinears       f(A,B,C) : f(B,C,A) : f(C,A,B), where f(A,B,C) = b sin B/2 + c sin C/2 - a sin A/2
Barycentrics  af(A,B,C) : bf(B,C,A) : cf(C,A,B)

The isoscelizer equations [h(X,A)]/a = [h(X,B)]/b = [h(X,C)]/c have solution X = X(504). (Peter Yff, 4/9/99)

X(504) lies on this line: 164,173  


X(505)

Trilinears       f(A,B,C) : f(B,C,A) : f(C,A,B), where f(A,B,C) = 1/(sin B/2 + sin C/2 - sin A/2)
Barycentrics  af(A,B,C) : bf(B,C,A) : cf(C,A,B)

The isoscelizer equations h(X,A)v(X,A) = h(X,B)v(X,B) = h(X,C)v(X,C) have solution X = X(505). (Peter Yff, 4/9/99)

X(505) lies on this line: 40, 164

X(505) = isogonal conjugate of X(164)
X(505) = X(266)-cross conjugate of X(1)


X(506)

Trilinears       f(A,B,C) : f(B,C,A) : f(C,A,B), where f(A,B,C) = (cos A/2)-2/3
Barycentrics  af(A,B,C) : bf(B,C,A) : cf(C,A,B)

The isoscelizer equations

[v(X,A)][area of t(X,A)] = [v(X,B)][area of t(X,B)] = [v(X,C)][area of t(X,C)]

have solution X = X(506). (Peter Yff, 4/9/99)


X(507)

Trilinears       f(A,B,C) : f(B,C,A) : f(C,A,B), where f(A,B,C) = (cos A/2)-1/2
Barycentrics  af(A,B,C) : bf(B,C,A) : cf(C,A,B)

The isoscelizer equations

[area of T(X,A)]/v(X,A) = [area of T(X,B)]/v(X,B) = [area of T(X,C)]/v(X,C)

have solution X = X(507). (Peter Yff, 4/9/99)


X(508)

Trilinears       a-1/2sec(A/2) : b-1/2sec(B/2) : c-1/2sec(C/2)
Barycentrics  a1/2sec(A/2) : b1/2sec(B/2) : c1/2sec(C/2)

The isoscelizer equations

a[area of T(X,A)] = b[area of T(X,B)] = c[area of T(X,C)]

have solution X = X(508). (Peter Yff, 4/9/99)


X(509)

Trilinears       f(A,B,C) : f(B,C,A) : f(C,A,B), where f(A,B,C) = (tan A/2)1/2
Barycentrics  af(A,B,C) : bf(B,C,A) : cf(C,A,B)

The isoscelizer equations

[area of T(X,A)]/a = [area of T(X,B)]/b = [area of T(X,C)]/c

have solution X = X(509). (Peter Yff, 4/9/99)


X(510)

Trilinears       f(a,b,c) : f(b,c,a) : f(c,a,b), where f(a,b,c) = b3/2 + c3/2 - a3/2
Barycentrics  af(a,b,c) : bf(b,c,a) : cf(c,a,b)

The isoscelizer equations

t(X,A)[area of T(X,A)]/a = t(X,B)[area of T(X,B)]/b = t(X,C)[area of T(X,C)]/c

have solution X = X(510). (Peter Yff, 4/9/99)



leftri Centers 511- 526 rightri
and 30 lie on the line at infinity.

Thus, each collection of collinearities comprises a family of parallel lines.
underbar

X(511) = ISOGONAL CONJUGATE OF X(98)

Trilinears       cos(A + ω) : cos(B + ω) : cos(C + ω)
Barycentrics  sin A cos(A + ω) : cos B cos(B + ω) : cos C cos(C + ω)

As the isogonal conjugate of a point on the circumcircle, X(511) lies on the line at infinity.

X(511) lies on these lines:
1,256   2,51   3,6   4,69 5,141   20,185   22,184   23,110   24,1092   25,394   26,206   30,512   40,1045   55,611   56,613   66,68   67,265   74,691   98,385   107,450   111,352   114,325   125,858   140,143   155,159   171,181   186,249   287,401   298,1080   299,383   343,427   381,599   549,597

X(511) = isogonal conjugate of X(98)
X(511) = isotomic conjugate of X(290)
X(511) = cevapoint of X(385) and X(401)
X(511) = X(I)-cross conjugate of X(J) for these (I,J): (4,114), (290,2), (297,232)
X(511) = crosspoint of X(I) and X(J) for these (I,J): (2,290), (297,325)
X(511) = X(3)-Hirst inverse of X(6)
X(511) = X(I)-line conjugate of X(J) for these (I,J): (3,6), (30,523)


X(512) = ISOGONAL CONJUGATE OF X(99)

Trilinears       a(b2 - c2) : b(c2 - a2) : c(a2 - b2)
Barycentrics  a2(b2 - c2) : b2(c2 - a2) : c2(a2 - b2)

X(512) is the point in which the line of the 1st and 2nd Brocard points meets the line at infinity.

X(512) lies on these lines: 1,875   4,879   30,511   32,878   39,881   74,842   99,805   110,249   111,843   187,237   316,850   660,1016   670,886

X(512) = isogonal conjugate of X(99)
X(512) = isotomic conjugate of X(670)
X(512) = X(I)-Ceva conjugate of X(J) for these (I,J): (4,115), (66,125), (99,39), (110,6), (112,32)
X(512) = crosspoint of X(I) and X(J) for these (I,J): (4,112), (6,110), (83,99)
X(512) = X(112)-line conjugate of X(30)


X(513) = ISOGONAL CONJUGATE OF X(100)

Trilinears       b - c : c - a : a - b
Barycentrics  ab - ac : bc - ba : ca - cb

As the isogonal conjugate of a point on the circumcircle, X(513) lies on the line at infinity.

X(513) lies on these lines: 1,764   6,1024   7,885   30,511   36,238   37,876   44,649   59,651   100,765   104,953   105,840   190,660   320,350   663,855   668,889   1052,1054

X(513) = X(244)-cross conjugate of X(1)
X(513) = X(I)-Ceva conjugate of X(J) for these (I,J): (1,244), (4,11), (100,1), (101,354), (108,56), (109,65), (190,37)

X(513) = isogonal conjugate of X(100)
X(513) = isotomic conjugate of X(668)
X(513) = crosspoint of X(I) and X(J) for these (I,J): (1,100), (4,108), (58,109), (86,190)
X(513) = X(I)-line conjugate of X(J) for these (I,J): (30,518), (36,238)


X(514) = ISOGONAL CONJUGATE OF X(101)

Trilinears       (b - c)/a : (c - a)/b : (a - b)/c
Barycentrics  b - c : c - a : a - b

As the isogonal conjugate of a point on the circumcircle, X(514) lies on the line at infinity.

X(514) lies on this line: 1,663   2,1022   10,764   30,511   101,664   109,929   190,1016   239,649   241,650   551,676   651,655   659,667   661,693

X(514) = isogonal conjugate of X(101)
X(514) = isotomic conjugate of X(190)
X(514) = X(I)-Ceva conjugate of X(J) for these (I,J): (4,116), (7,11), (75,244), (100,142), (190,2)
X(514) = X(I)-cross conjugate of X(J) for these (I,J): (11,7), (244,75)
X(514) = crosspoint of X(2) and X(190)


X(515) = ISOGONAL CONJUGATE OF X(102)

Trilinears       f(a,b,c) : f(b,c,a) : f(c,a,b), where f(a,b,c) = (b + c)sec A - b sec B - c sec C
Barycentrics  af(a,b,c) : bf(b,c,a) cf(c,a,b)

As the isogonal conjugate of a point on the circumcircle, X(515) lies on the line at infinity.

X(515) lies on these lines: 1,4   3,10   8,20   29,947   30,511   36,80   55,1012   103,929   119,214   153,908   165,376   281,610   284,1065   381,551

X(515) = isogonal conjugate of X(102)
X(515) = X(4)-Ceva conjugate of X(117)


X(516) = ISOGONAL CONJUGATE OF X(103)

Trilinears       1/f(a,b,c) : 1/f(b,c,a) : 1/f(c,a,b), where f(a,b,c) : f(b,c,a) : f(c,a,b) = X(103)
Barycentrics  a/f(a,b,c) : b/f(b,c,a) c/f(c,a,b)

As the isogonal conjugate of a point on the circumcircle, X(516) lies on the line at infinity.

X(516) lies on these lines:
1,7   2,165   3,142   4,9   8,144   30,511   35,411   55,226   57,497   65,950   80,655   100,908   102,929   103,927   118,910   200,329   238,673   354,553   355,382   376,551   993,1012

X(516) = isogonal conjugate of X(103)
X(516) = X(4)-Ceva conjugate of X(118)


X(517) = ISOGONAL CONJUGATE OF X(104)

Trilinears       -1 + cos B + cos C : -1 + cos C + cos A : -1 + cos A + cos B
Barycentrics  (sin A)(-1 + cos B + cos C) : (sin B)(-1 + cos C + cos A) : (sin C)(-1 + cos A + cos B)

As the isogonal conjugate of a point on the circumcircle, X(517) lies on the line at infinity.

X(517) lies on these lines:
1,3   2,392   4,8   5,10   6,998   7,1000   9,374   19,219   20,145   30,511   37,573   42,1064   63,956   78,945   100,953   101,910   104,901   119,908   169,220   210,381   226,495   238,1052   389,950   549,551   572,1100   580,595   582,602   938,1058   1042,1066

X(517) = isogonal conjugate of X(104)
X(517) = X(4)-Ceva conjugate of X(119)
X(517) = crosspoint of X(I) and X(J) for these (I,J): (1,80), (7,88)


X(518) = ISOGONAL CONJUGATE OF X(105)

Trilinears       f(a,b,c) : f(b,c,a) : f(c,a,b), where f(a,b,c) = ab + ac - b2 - c2
Barycentrics  af(a,b,c) : bf(b,c,a) cf(c,a,b)

As the isogonal conjugate of a point on the circumcircle, X(518) lies on the line at infinity.

X(518) lies on these lines:
1,6   2,210   7,8   10,141   11,908   30,511   38,42   43,982   55,63   56,78   57,200   59,765   144,145   209,306   239,335   244,899   329,497   551,597   583,1009   612,940   896,902   997,999

X(518) = isogonal conjugate of X(105)
X(518) = X(I)-Ceva conjugate of X(J) for these (I,J): (4,120), (335,37)
X(518) = crosspoint of X(1) and X(291)
X(518) = X(1)-Hirst inverse of X(9)
X(518) = X(I)-line conjugate of X(J) for these (I,J): (1,6), (30,513)


X(519) = ISOGONAL CONJUGATE OF X(106)

Trilinears       (2a - b - c)/a : (2b - c - a)/b : (2c - a - b)/c
Barycentrics  2a - b - c : 2b - c - a : 2c - a - b

As the isogonal conjugate of a point on the circumcircle, X(519) lies on the line at infinity.

X(519) lies on these lines: 1,2   6,996   9,1000   30,511   36,100   40,376   55,956   58,1043   65,553   72,950   80,908   210,392   238,765   320,668   355,381   447,648   594,1100   672,1018   751,984

X(519) = isogonal conjugate of X(106)
X(519) = isotomic conjugate of X(903)
X(519) = X(I)-Ceva conjugate of X(J) for these (I,J): (4,121), (80,10)


X(520) = ISOGONAL CONJUGATE OF X(107)

Trilinears       (cos A)(sin 2B - sin 2C) : (cos B)(sin 2C - sin 2A) : (cos C)(sin 2A - sin 2B)
Barycentrics  (sin 2A)(sin 2B - sin 2C) : (sin 2B)(sin 2C - sin 2A) : (sin 2C)(sin 2A - sin 2B)

As the isogonal conjugate of a point on the circumcircle, X(520) lies on the line at infinity.

X(520) lies on these lines: 30,511   69,879   110,250   340,850   647,652

X(520) = isogonal conjugate of X(107)
X(520) = X(I)-Ceva conjugate of X(J) for these (I,J): (4,122), (68,125), (110,3)
X(520) = crosspoint of X(3) and X(110)


X(521) = ISOGONAL CONJUGATE OF X(108)

Trilinears       (sec B - sec C)(csc A) : (sec C - sec A)(csc B) : (sec A - sec B)(csc C)
Barycentrics  sec B - sec C : sec C - sec A : sec A - sec B

As the isogonal conjugate of a point on the circumcircle, X(521) lies on the line at infinity.

X(521) lies on these lines: 30,511   59,100   650,1021   656,810

X(521) = isogonal conjugate of X(108)
X(521) = X(I)-Ceva conjugate of X(J) for these (I,J): (4,123), (100,3)
X(521) = crosspoint of X(8) and X(100)


X(522) = ISOGONAL CONJUGATE OF X(109)

Trilinears       (cos B - cos C)(csc A) : (cos C - cos A)(csc B) : (cos A - cos B)(csc C)
Barycentrics  cos B - cos C : cos C - cos A : cos A - cos B

As the isogonal conjugate of a point on the circumcircle, X(522) lies on the line at infinity.

X(522) lies on this line: 9,657   30,511   100,655   101,929   190,666   240,656   243,652

X(522) = isogonal conjugate of X(109)
X(522) = isotomic conjugate of X(664)
X(522) = X(I)-Ceva conjugate of X(J) for these (I,J): (4,124), (8,11), (100,10), (190,9)
X(522) = X(11)-cross conjugate of X(8)
X(522) = crosspoint of X(I) and X(J) for these (I,J): (21,100), (75,190)


X(523) = ISOGONAL CONJUGATE OF X(110)

Trilinears       sin(B - C) : sin(C - A) : sin(A - B)
Barycentrics  b2 - c2 : c2 - a2 : a2 - b2

As the isogonal conjugate of a point on the circumcircle, X(523) lies on the line at infinity.

X(523) lies on these lines: 6,879   11,1090   23,385   30,511   69,655   74,477   75,876   98,842   99,691   110,476   112,935   141,882   230,231   250,648   325,684

X(523) = X(I)-Ceva conjugate of X(J) for these (I,J): (1,11), (2,115), (4,125), (99,2), (100,442), (107,4), (108,429), (108,429), (110,5), (112,427), (254,136), (476,30)

X(523) = isogonal conjugate of X(110)
X(523) = isotomic conjugate of X(99)
X(523) = cevapoint of X(2) and X(148)
X(523) = X(I)-cross conjugate of X(J) for these (I,J): (115,2), (125,4)
X(523) = crosspoint of X(I) and X(J) for these (I,J): (2,99), (4,107), (54,110), (112,251)
X(523) = X(30)-line conjugate of X(511)


X(524) = ISOGONAL CONJUGATE OF X(111)

Trilinears       (2a2 - b2 - c2)/a : (2b2 - c2 - a2)/b : (2c2 - a2 - b2)/c
Barycentrics  2a2 - b2 - c2 : 2b2 - c2 - a2 : 2c2 - a2 - b2

As the isogonal conjugate of a point on the circumcircle, X(524) lies on the line at infinity.

X(524) lies on these lines: 2,6   5,576   30,511   53,317   67,858   76,598   99,843   140,575   182,549   239,320   297,340   316,594   319,594   397,633   398,634

X(524) = isogonal conjugate of X(111)
X(524) = isotomic conjugate of X(671)
X(524) = X(I)-Ceva conjugate of X(J) for these (I,J): (4,126), (67,141)
X(524) = X(187)-cross conjugate of X(468)
X(524) = X(I)-line conjugate of X(J) for these (I,J): (2,6), (30,512)


X(525) = ISOGONAL CONJUGATE OF X(112)

Trilinears       (b cos B - c cos C)/a : (c cos C - a cos A)/b : (a cos A - b cos B)/c
Barycentrics  b cos B - c cos C : c cos C - a cos A : a cos A - b cos B

As the isogonal conjugate of a point on the circumcircle, X(525) lies on the line at infinity.

X(525) lies on these lines: 3,878   30,511   99,249   110,935   297,850   323,401   441,647

X(525) = X(I)-Ceva conjugate of X(J) for these (I,J): (4,127), (69,125), (76,339), (99,3), (110,141), (190,440), (253, 122)

X(525) = isogonal conjugate of X(112)
X(525) = isotomic conjugate of X(648)
X(525) = X(I)-cross conjugate of X(J) for these (I,J): (115,68), (122,253), (125,69)
X(525) = crosspoint of X(76) and X(99)


X(526) = ISOGONAL CONJUGATE OF X(476)

Trilinears       f(A,B,C) : f(B,C,A) : f(C,A,B), where f(A,B,C) = (1 + 2 cos 2A)sin(B - C)
Barycentrics  (sin A)f(A,B,C) : (sin B)f(B,C,A) : (sin C)f(C,A,B)

As the isogonal conjugate of a point on the circumcircle, X(526) lies on the line at infinity.

X(526) = isogonal conjugate of X(476)
X(526) lies on these lines: 30,511   67,879   110,351
X(526) = crosspoint of X(74) and X(110)



leftri Centers 527- 565 rightri
were added to ETC on 1/1/01.

underbar

X(527) = DIRECTION OF VECTOR AX + BX + CX, where X = X(7)

Trilinears       f(a,b,c) : f(b,c,a) : f(c,a,b), where
                        f(a,b,c) = (2ax - by - cz)/a, x = x(a,b,c) = 1/[a(b + c - a)], y = x(b,c,a), z = x(c,a,b)

Barycentrics  af(a,b,c) : bf(b,c,a) : cf(c,a,b)

X(527) lies on the line at infinity.

X(527) lies on these lines: 2,7   30,511   44,1086   190,320   551,993   666,673


X(528) = DIRECTION OF VECTOR AX + BX + CX, where X = X(11)

Trilinears       f(a,b,c) : f(b,c,a) : f(c,a,b), where
                        f(a,b,c) = (2ax - by - cz)/a, x = x(A,B,C) = 1 - cos(B-C), y = x(B,C,A), z = x(C,A,B)

Barycentrics  af(a,b,c) : bf(b,c,a) : cf(c,a,b)

X(528) lies on the line at infinity.

X(528) lies on these lines: 1,1086   2,11   7,664   8,190   9,80   30,511   104,376   119,381   142,214

X(528) = isogonal conjugate of X(840)


X(529) = DIRECTION OF VECTOR AX + BX + CX, where X = X(12)

Trilinears       f(a,b,c) : f(b,c,a) : f(c,a,b), where
                        f(a,b,c) = (2ax - by - cz)/a, x = x(A,B,C) = 1 + cos(B-C), y = x(B,C,A), z = x(C,A,B)

Barycentrics  af(a,b,c) : bf(b,c,a) : cf(c,a,b)

X(529) lies on the line at infinity.

X(529) lies on these lines: 2,12   30,511   495,993   1001,1056


X(530) = DIRECTION OF VECTOR AX + BX + CX, where X = X(13)

Trilinears       f(a,b,c) : f(b,c,a) : f(c,a,b), where
                        f(a,b,c) = (2ax - by - cz)/a, x = x(A,B,C) = csc(A + π/3), y = x(B,C,A), z = x(C,A,B)

Barycentrics  af(a,b,c) : bf(b,c,a) : cf(c,a,b)

X(530) lies on the line at infinity.

X(530) lies on these lines: 2,13   14,671   30,511   99,299   115,395   187,396   298,316


X(531) = DIRECTION OF VECTOR AX + BX + CX, where X = X(14)

Trilinears       f(a,b,c) : f(b,c,a) : f(c,a,b), where
                        f(a,b,c) = (2ax - by - cz)/a, x = x(A,B,C) = csc(A - π/3), y = x(B,C,A), z = x(C,A,B)

Barycentrics  af(a,b,c) : bf(b,c,a) : cf(c,a,b)

X(531) lies on the line at infinity.

X(531) lies on these lines: 2,14   13,671   30,511   99,298   115,396   187,395   299,316


X(532) = DIRECTION OF VECTOR AX + BX + CX, where X = X(17)

Trilinears       f(a,b,c) : f(b,c,a) : f(c,a,b), where
                        f(a,b,c) = (2ax - by - cz)/a, x = x(A,B,C) = csc(A + π/6), y = x(B,C,A), z = x(C,A,B)

Barycentrics  af(a,b,c) : bf(b,c,a) : cf(c,a,b)

X(532) lies on the line at infinity.

X(532) lies on these lines: 2,17   13,298   14,622   15,616   16,299   30,511   395,624   396,618   397,635


X(533) = DIRECTION OF VECTOR AX + BX + CX, where X = X(18)

Trilinears       f(a,b,c) : f(b,c,a) : f(c,a,b), where
                        f(a,b,c) = (2ax - by - cz)/a, x = x(A,B,C) = csc(A - π/6), y = x(B,C,A), z = x(C,A,B)

Barycentrics  af(a,b,c) : bf(b,c,a) : cf(c,a,b)

X(533) lies on the line at infinity.

X(533) lies on these lines: 2,18    13,621   14,299   15,298  16,617    30,511   395,619   396,623   398,636


X(534) = DIRECTION OF VECTOR AX + BX + CX, where X = X(19)

Trilinears       f(a,b,c) : f(b,c,a) : f(c,a,b), where
                        f(a,b,c) = (2ax - by - cz)/a, x = x(A,B,C) = tan A, y = x(B,C,A), z = x(C,A,B)

Barycentrics  af(a,b,c) : bf(b,c,a) : cf(c,a,b)

X(534) lies on the line at infinity.

X(534) lies on these lines: 2,19   30,511


X(535) = DIRECTION OF VECTOR AX + BX + CX, where X = X(36)

Trilinears       f(a,b,c) : f(b,c,a) : f(c,a,b), where
                        f(a,b,c) = (2ax - by - cz)/a, x = x(A,B,C) = 1 - 2 cos A, y = x(B,C,A), z = x(C,A,B)

Barycentrics  af(a,b,c) : bf(b,c,a) : cf(c,a,b)

X(535) lies on the line at infinity.

X(535) lies on these lines: 2,36   30,511   63,484    214,908   226,551


X(536) = DIRECTION OF VECTOR AX + BX + CX, where X = X(37)

Trilinears       f(a,b,c) : f(b,c,a) : f(c,a,b), where
                        f(a,b,c) = (2ax - by - cz)/a, x = x(a,b,c) = b + c, y = x(b,c,a), z = x(c,a,b)

Barycentrics  af(a,b,c) : bf(b,c,a) : cf(c,a,b)

X(536) lies on the line at infinity.

X(536) lies on these lines: 2,37   30,511   44,190   335,903   894,1100

X(536) = isogonal conjugate of X(739)


X(537) = DIRECTION OF VECTOR AX + BX + CX, where X = X(38)

Trilinears       f(a,b,c) : f(b,c,a) : f(c,a,b), where
                        f(a,b,c) = (2ax - by - cz)/a, x = x(a,b,c) = b2 + c2, y = x(b,c,a), z = x(c,a,b)

Barycentrics  af(a,b,c) : bf(b,c,a) : cf(c,a,b)

X(537) lies on the line at infinity.

X(537) lies on these lines: 1,190   2,38   10,1086   30,511   37,551   75,668


X(538) = DIRECTION OF VECTOR AX + BX + CX, where X = X(39)

Trilinears       f(a,b,c) : f(b,c,a) : f(c,a,b), where
                        f(a,b,c) = (2ax - by - cz)/a, x = x(a,b,c) = a(b2 + c2), y = x(b,c,a), z = x(c,a,b)

Barycentrics  af(a,b,c) : bf(b,c,a) : cf(c,a,b)

X(538) lies on the line at infinity.

X(538) lies on these lines: 2,39   30,511   32,1003   99,187   115,325   148,316   183,574   230,620   350,1015

X(538) = isogonal conjugate of X(729)


X(539) = DIRECTION OF VECTOR AX + BX + CX, where X = X(54)

Trilinears       f(a,b,c) : f(b,c,a) : f(c,a,b), where
                        f(a,b,c) = (2ax - by - cz)/a, x = x(A,B,C) = 1/cos(B-C), y = x(B,C,A), z = x(C,A,B)

Barycentrics  af(a,b,c) : bf(b,c,a) : cf(c,a,b)

X(539) lies on the line at infinity.

X(539) lies on these lines: 2,54   30,511   155,195


X(540) = DIRECTION OF VECTOR AX + BX + CX, where X = X(58)

Trilinears       f(a,b,c) : f(b,c,a) : f(c,a,b), where
                        f(a,b,c) = (2ax - by - cz)/a, x = x(a,b,c) = a/(b + c), y = x(b,c,a), z = x(c,a,b)

Barycentrics  af(a,b,c) : bf(b,c,a) : cf(c,a,b)

X(540) lies on the line at infinity.

X(540) lies on these lines: 2,58   30,511   340,447


X(541) = DIRECTION OF VECTOR AX + BX + CX, where X = X(74)

Trilinears       f(a,b,c) : f(b,c,a) : f(c,a,b), where
                        f(a,b,c) = (2ax - by - cz)/a, x = x(A,B,C) = 1/(cos A - 2 cos B cos C), y = x(B,C,A), z = x(C,A,B)

Barycentrics  af(a,b,c) : bf(b,c,a) : cf(c,a,b)

X(541) lies on the line at infinity.

X(541) lies on these lines: 2,74   30,511   110,376   125,381   394,399

X(541) = isogonal conjugate of X(841)


X(542) = DIRECTION OF VECTOR AX + BX + CX, where X = X(98)

Trilinears       f(a,b,c) : f(b,c,a) : f(c,a,b), where
                        f(a,b,c) = (2ax - by - cz)/a, x = x(A,B,C) = sec(A + ω), y = x(B,C,A), z = x(C,A,B)

Barycentrics  af(a,b,c) : bf(b,c,a) : cf(c,a,b)

X(542) lies on the line at infinity.

X(542) lies on these lines: 2,98   3,67   4,576   5,575   6,13   30,511   69,74   141,549   146,148

X(542) = isogonal conjugate of X(842)


X(543) = DIRECTION OF VECTOR AX + BX + CX, where X = X(99)

Trilinears       f(a,b,c) : f(b,c,a) : f(c,a,b), where
                        f(a,b,c) = (2ax - by - cz)/a, x = x(a,b,c) = bc/(b2 - c2), y = x(b,c,a), z = x(c,a,b)

Barycentrics  af(a,b,c) : bf(b,c,a) : cf(c,a,b)

X(543) lies on the line at infinity.

X(543) lies on these lines: 2,99   30,511   98,376   114,381

X(543) = isogonal conjugate of X(843)


X(544) = DIRECTION OF VECTOR AX + BX + CX, where X = X(101)

Trilinears       f(a,b,c) : f(b,c,a) : f(c,a,b), where
                        f(a,b,c) = (2ax - by - cz)/a, x = x(a,b,c) = a/(b - c), y = x(b,c,a), z = x(c,a,b)

Barycentrics  af(a,b,c) : bf(b,c,a) : cf(c,a,b)

X(544) lies on the line at infinity.

X(544) lies on these lines: 2,101   30,511   63,1018   103,376   118,381


X(545) = DIRECTION OF VECTOR AX + BX + CX, where X = X(190)

Trilinears       f(a,b,c) : f(b,c,a) : f(c,a,b), where
                        f(a,b,c) = (2ax - by - cz)/a, x = x(a,b,c) = bc/(b - c), y = x(b,c,a), z = x(c,a,b)

Barycentrics  af(a,b,c) : bf(b,c,a) : cf(c,a,b)

X(545) lies on the line at infinity.

X(545) lies on these lines: 2,45   30,511


X(546) = NINE-POINT CENTER OF X(4)-EULER MIDWAY TRIANGLE

Trilinears       f(A,B,C) : f(B,C,A) : f(C,A,B), where
                        f(A,B,C) = 3 cos(B - C) - 2 cos A

Barycentrics  (sin A)f(A,B,C) : (sin B)f(B,C,A) : (sin C)f(C,A,B)

X(546) lies on the Euler line. (Antreas Hatzipolakis, 1/20/00, Hyacinthos #201)

X(546) lies on these lines: 2,3   13,398   14,397   113,137   156,578   946,952

X(546) = inverse of X(382) in the orthocentroidal circle
X(546) = complement of X(550)


X(547) = CENTROID OF X(5)-EULER MIDWAY TRIANGLE

Trilinears       f(A,B,C) : f(B,C,A) : f(C,A,B), where
                        f(A,B,C) = 5 cos(B - C) + 2 cos A

Barycentrics  (sin A)f(A,B,C) : (sin B)f(B,C,A) : (sin C)f(C,A,B)

X(547) lies on the Euler line. (Antreas Hatzipolakis, 1/20/00, Hyacinthos #201)

X(547) lies on these lines: 2,3   551,952

X(547) = complement of X(549)


X(548) = DE LONGCHAMPS POINT OF X(5)-EULER MIDWAY TRIANGLE

Trilinears       f(A,B,C) : f(B,C,A) : f(C,A,B), where
                        f(A,B,C) = - cos(B - C) + 6 cos A

Barycentrics  (sin A)f(A,B,C) : (sin B)f(B,C,A) : (sin C)f(C,A,B)

X(548) lies on the Euler line. (Antreas Hatzipolakis, 1/20/00, Hyacinthos #201)


X(549) = ORTHOCENTER OF X(2)-EULER MIDWAY TRIANGLE

Trilinears       f(A,B,C) : f(B,C,A) : f(C,A,B), where
                        f(A,B,C) = cos(B - C) + 4 cos A

Barycentrics  (sin A)f(A,B,C) : (sin B)f(B,C,A) : (sin C)f(C,A,B)

X(549) lies on the Euler line. (Antreas Hatzipolakis, 1/20/00, Hyacinthos #201)

X(549) lies on these lines: 2,3   15,395   16,396   35,496   36,495   141,542   182,524   230,574   302,617   303,616   511,597   517,551

X(549) = complement of X(381)
X(549) = anticomplement of X(547)


X(550) = ORTHOCENTER OF X(20)-EULER MIDWAY TRIANGLE

Trilinears       f(A,B,C) : f(B,C,A) : f(C,A,B), where
                        f(A,B,C) = - cos(B - C) + 4 cos A

Barycentrics  (sin A)f(A,B,C) : (sin B)f(B,C,A) : (sin C)f(C,A,B)

X(550) lies on the Euler line. (Antreas Hatzipolakis, 1/20/00, Hyacinthos #201)

X(550) lies on these lines: 2,3   15,397   16,398   35,495   36,496   40,952   74,930   156,1092   165,355

X(550) = complement of X(382) X(550) = anticomplement of X(546)


X(551) = INCENTER OF X(1)-EULER MIDWAY TRIANGLE

Trilinears       (4a + b + c)/a : (4b + c + a)/b : (4c + a + b)/c
Barycentrics  4a + b + c : 4b + c + a : 4c + a + b

X(551) lies on these lines: 1,2   30,946   37,537   56,553   86,99   142,214   226,535   354,392   376,516   381,515   514,676   517,549   518,597   527,993   547,952

(Antreas Hatzipolakis, 1/24/00, Hyacinthos #223)


X(552)  

Trilinears       1/[a(b + c - a)(b + c)2] : 1/[b(c +a - b)(c + a)2] : 1/[c(a + b - c)(a + b)2]
Barycentrics  1/[(b+c-a)(b+c)2] : 1/[(c+a-b)(c+a)2] : 1/[(a+b-c)(a+b)2]

X(552) lies on this line: 261,873

(Floor van Lamoen, 1/30/00, Hyacinthos #255)


X(553)  

Trilinears       bc(2a + b + c)/(b + c - a) : ca(2b + c + a)/(c + a - b) : ab/(2c + a + b)/(a + b - c)
Barycentrics  (2a + b + c)/(b + c - a) : (2b + c + a)/(c + a - b) : /(2c + a + b)/(a + b - c)

X(553) lies on these lines: 1,376   2,7   30,942   56,551   65,519   354,516

(Floor van Lamoen, 1/30/00, Hyacinthos #257)


X(554)  

Trilinears       sec(A/2) csc(A/2 + π/3) : sec(B/2) csc(B/2 + π/3) : sec(C/2) csc(C/2 + π/3)
Barycentrics  sin A sec(A/2) csc(A/2 + π/3) : sin B sec(B/2) csc(B/2 + π/3) : sin C sec(C/2) csc(C/2 + π/3)

X(554) lies on these lines: 1,30   7,1082   14,226   75,299

Clark Kimberling, "Major Centers of Triangles," Amer. Math. Monthly 104 (1997) 431-438; in (9) on page 435, take Y = X(13).


X(555)  

Trilinears       sec3(A/2) : sec3(B/2) : sec3(C/2)
Barycentrics  sin A sec3(A/2) : sin B sec3(B/2) : sin C sec3(C/2)

X(555) lies on these lines: 7,177   234,1088

Clark Kimberling, "Major Centers of Triangles," Amer. Math. Monthly 104 (1997) 431-438; in (9) on page 435, take Y = X(7).


X(556)  

Trilinears       csc A csc A/2 : csc B csc B/2 : csc C csc C/2
Barycentrics  csc A/2 : csc B/2 : csc C/2

X(556) lies on these lines: 8,177   74,234

X(556) = isotomic conjugate of X(174)

Clark Kimberling, "Major Centers of Triangles," Amer. Math. Monthly 104 (1997) 431-438; in (9) on page 435, take Y = X(8).


X(557)  

Trilinears       sec A/2 cot A/4 : sec B/2 cot B/4 : sec C/2 cot C/4
Barycentrics  cos A/2 cot A/4 : cos B/2 cot B/4 : cos C/2 cot C/4

X(557) lies on this line: 2,178

Clark Kimberling, "Major Centers of Triangles," Amer. Math. Monthly 104 (1997) 431-438; in (9) on page 435, take Y = X(9).


X(558)  

Trilinears       sec A/2 tan A/4 : sec B/2 tan B/4 : sec C/2 tan C/4
Barycentrics  sin2(A/4) : sin2(B/4) : sin2(C/4)

X(558) lies on this line: 2,178

Clark Kimberling, "Major Centers of Triangles," Amer. Math. Monthly 104 (1997) 431-438; in (9) on page 435, take Y = X(57).


X(559)  

Trilinears       (sec A/2) sin(A/2 + π/3) : (sec B/2) sin(B/2 + π/3) : (sec C/2) sin(C/2 + π/3)
Barycentrics  (sin A/2) sin(A/2 + π/3) : (sin B/2) sin(B/2 + π/3) : (sin C/2) sin(C/2 + π/3)

X(559) lies on these lines: 1,3   14,226   299,319

Clark Kimberling, "Major Centers of Triangles," Amer. Math. Monthly 104 (1997) 431-438; in (9) on page 435, take Y = X(15).


X(560)  4th POWER POINT

Trilinears       a4 : b4 : c4
Barycentrics  a5 : b5 : c5

X(560) lies on these lines: 1,82   31,48   41,872   42,584   100,697   101,713   110,715   717,825   719,827

X(560) = isogonal conjugate of X(561)


X(561)  ISOGONAL CONJUGATE OF 4th POWER POINT

Trilinears       a - 4 : b - 4 : c - 4
Barycentrics  a - 3 : b - 3 : c - 3

X(561) lies on these lines: 1,718   2,716   6,720   31,722   32,724   38,75   63,799   76,321   92,304   313,696

X(561) = isogonal conjugate of X(560)
X(561) = isotomic conjugate of X(31)


X(562)  

Trilinears       csc A tan 3A : csc B tan 3B : csc C tan 3C
Barycentrics  tan 3A : tan 3B : tan 3C

X(562) lies on this line: 4,93

Clark Kimberling and Cyril Parry, "Products, Square Roots, and Layers in Triangle Geometry," Mathematics and Informatics Quarterly 10 (2000) 9-22; on page 21, section 8.


X(563)  

Trilinears        sin 4A : sin 4B : sin 4C
Barycentrics  sin A sin 4A : sin B sin 4B : sin C sin 4C

X(563) lies on these lines: 19,163   48,255

Clark Kimberling and Cyril Parry, "Products, Square Roots, and Layers in Triangle Geometry," Mathematics and Informatics Quarterly 10 (2000) 9-22; on page 21, section 8.


X(564)  

Trilinears        cos(2B - 2C) : cos(2C - 2A) : cos(2A - 2B)
Barycentrics  sin A cos(2B - 2C) : sin B cos(2C - 2A) : sin C cos(2A - 2B)

X(564) lies on these lines: 1,1048   47,91

Clark Kimberling and Cyril Parry, "Products, Square Roots, and Layers in Triangle Geometry," Mathematics and Informatics Quarterly 10 (2000) 9-22; on page 21, section 8.


X(565)  

Trilinears        cos(3B - 3C) : cos(3C - 3A) : cos(3A - 3B)
Barycentrics  sin A cos(3B - 3C) : sin B cos(3C - 3A) : sin C cos(3A - 3B)

X(565) lies on these lines: 49,93   143,324

Clark Kimberling and Cyril Parry, "Products, Square Roots, and Layers in Triangle Geometry," Mathematics and Informatics Quarterly 10 (2000) 9-22; on page 21, section 8.



leftri Centers 566- 584 rightri
are on the Brocard axis, L(3,6). Each is the center X of a circle
meeting the sides of triangle ABC with three equal angles at X.
Let AB, AC, BC, BA, CA, CB denote the meeting-points; e.g., AB and CB
are on side CA. The equal angles are given by

D = angle(ABXAC) = angle(BCXBA) = angle(CAXCB)

Then trilinears for X are given by

X = sin A + cot D/2 cos A : sin B + cot D/2 cos B : sin C + cot D/2 cos C.

Definitions: Y is the orthogonal of X if D(X) + D(Y) = π/2;
Y is the harmonic of X if X and Y are harmonic conjugates with respect to X(3) and X(6);
Y is the orthoharmonic if Y is the harmonic of the orthogonal of X.

For a figure and details, see Edward Brisse, "Some properties of points on the axis of Brocard."
underbar

X(566) = HARMONIC OF X(50)

Trilinears        f(A,B,C) : f(B,C,A) : f(C,A,B), where f(A,B,C) = sin A + cot D/2 cos A,
                        cot D/2 = 4*area/(a2 + b2 + c2 - 6r2), where r = abc/(4*area)

Barycentrics  (sin A)f(A,B,C): (sin B)f(B,C,A) : (sin C)f(C,A,B)

X(566) lies on these lines: 2,94   3,6

X(566) = inverse of X(50) in the Brocard circle

Edward Brisse, as cited above X(566), page 7.


X(567) = ORTHOGONAL OF X(50)

Trilinears        f(A,B,C) : f(B,C,A) : f(C,A,B), where f(A,B,C) = sin A + cot D/2 cos A,
                        cot D/2 = (a2 + b2 + c2 - 6r2)/(4*area), where r = abc/(4*area)

Barycentrics  (sin A)f(A,B,C): (sin B)f(B,C,A) : (sin C)f(C,A,B)

X(567) lies on these lines: 3,6   5,49   184,381

X(567) = inverse of X(568) in the Brocard circle

Edward Brisse, as cited above X(566), page 7.


X(568) = ORTHOHARMONIC OF X(50)

Trilinears        f(A,B,C) : f(B,C,A) : f(C,A,B), where f(A,B,C) = sin A + cot D/2 cos A,
                        cot D/2 = (6r2 - a2 - b2 - c2)/(4*area), where r = abc/(4*area)

Barycentrics  (sin A)f(A,B,C): (sin B)f(B,C,A) : (sin C)f(C,A,B)

X(568) lies on these lines: 3,6   4,94   24,49   51,381   68,973   185,382

X(568) = inverse of X(567) in the Brocard circle

Edward Brisse, as cited above X(566), page 7.


X(569) = HARMONIC OF X(52)

Trilinears        f(A,B,C) : f(B,C,A) : f(C,A,B), where f(A,B,C) = sin A + cot D/2 cos A,
                        cot D/2 = (2e3 + e2 - e1)/[64*(area)3], where
                        e1 = a6 + b6 + c6
                        e2 = a4(b2 + c2) + b4(c2 + a2) + c4(a2 + b2)
                        e3 = a2b2c2

Barycentrics  (sin A)f(A,B,C): (sin B)f(B,C,A) : (sin C)f(C,A,B)

X(569) lies on these lines: 2,54   3,6   5,156   26,51   140,343

X(569) = inverse of X(52) in the Brocard circle

Edward Brisse, as cited above X(566), page 7.


X(570) = ORTHOGONAL OF X(52)

Trilinears        f(A,B,C) : f(B,C,A) : f(C,A,B), where f(A,B,C) = sin A + cot D/2 cos A,
                        cot D/2 = [64*(area)3]/(2e3 + e2 - e1), where
                        e1, e2, e3 are as for X(569)

Barycentrics  (sin A)f(A,B,C): (sin B)f(B,C,A) : (sin C)f(C,A,B)

X(570) lies on these lines: 2,311   3,6   53,232   115,128   140,231   157,184

X(570) = inverse of X(571) in the Brocard circle
X(570) = complement of X(311)

Edward Brisse, as cited above X(566), page 7.


X(571) = ORTHOHARMONIC OF X(52)

Trilinears        f(A,B,C) : f(B,C,A) : f(C,A,B), where f(A,B,C) = sin A + cot D/2 cos A,
                        cot D/2 = [64*(area)3]/(e1 - 2e3 - e2), where
                        e1, e2, e3 are as for X(569)

Barycentrics  (sin A)f(A,B,C): (sin B)f(B,C,A) : (sin C)f(C,A,B)

X(571) lies on these lines: 3,6   4,96   66,248   112,393   160,184   206,237   230,427   608,913

X(571) = inverse of X(570) in the Brocard circle

Edward Brisse, as cited above X(566), page 7.


X(572) = ORTHOGONAL OF X(58)

Trilinears        f(A,B,C) : f(B,C,A) : f(C,A,B), where f(A,B,C) = sin A + cot D/2 cos A,
                        cot D/2 = (a + b + c)2/(4*area)

Barycentrics  (sin A)f(A,B,C): (sin B)f(B,C,A) : (sin C)f(C,A,B)

X(572) lies on these lines: 1,604   3,6   9,48   51,199   54,71   103,825   165,1051   169,610   184,1011   219,947   261,662   517,1100   594,952   631,966

X(572) = inverse of X(573) in the Brocard circle

Edward Brisse, as cited above X(566), page 7.


X(573) = ORTHOHARMONIC OF X(58)

Trilinears        f(A,B,C) : f(B,C,A) : f(C,A,B), where f(A,B,C) = sin A + cot D/2 cos A,
                        cot D/2 = - (a + b + c)2/(4*area)

Barycentrics  (sin A)f(A,B,C): (sin B)f(B,C,A) : (sin C)f(C,A,B)

X(573) lies on these lines: 1,941   3,6   4,9   20,391   36,604   37,517   43,165   51,1011   55,181   101,102   109,478   184,199   256,981   346,1018   347,1020

X(573) = inverse of X(572) in the Brocard circle

Edward Brisse, as cited above X(566), page 7.


X(574) = HARMONIC OF X(187)

Trilinears        f(A,B,C) : f(B,C,A) : f(C,A,B), where f(A,B,C) = sin A + cot D/2 cos A,
                        cot D/2 = 12*area/(a2 + b2 + c2)

Barycentrics  (sin A)f(A,B,C): (sin B)f(B,C,A) : (sin C)f(C,A,B)

X(574) lies on these lines: 2,99   3,6   55,1015   110,353   183,538   230,549   232,378   805,843

X(574) = isogonal conjugate of X(598)
X(574) = inverse of X(187) in the Brocard circle

Edward Brisse, as cited above X(566), page 7.


X(575) = ORTHOGONAL OF X(187)

Trilinears        f(A,B,C) : f(B,C,A) : f(C,A,B), where f(A,B,C) = sin A + cot D/2 cos A,
                        cot D/2 = (a2 + b2 + c2)/(12*area)

Barycentrics  (sin A)f(A,B,C): (sin B)f(B,C,A) : (sin C)f(C,A,B)

X(575) lies on these lines: 3,6   4,598   5,542   23,51   54,895   110,373   140,524   141,629

X(575) = inverse of X(576) in the Brocard circle

Edward Brisse, as cited above X(566), page 7.


X(576) = ORTHOHARMONIC OF X(187)

Trilinears        f(A,B,C) : f(B,C,A) : f(C,A,B), where f(A,B,C) = sin A + cot D/2 cos A,
                        cot D/2 = - (a2 + b2 + c2)/(12*area)

Barycentrics  (sin A)f(A,B,C): (sin B)f(B,C,A) : (sin C)f(C,A,B)

X(576) lies on these lines: 3,6   4,542   5,524   23,184   140,597   262,385

X(576) = inverse of X(575) in the Brocard circle

Edward Brisse, as cited above X(566), page 7.


X(577) = HARMONIC OF X(216)

Trilinears        f(A,B,C) : f(B,C,A) : f(C,A,B), where f(A,B,C) = sin A + cot D/2 cos A,
                        cot D/2 = - 8*(area)3/(a2b2c2 cos A cos B cos C)

Barycentrics  (sin A)f(A,B,C): (sin B)f(B,C,A) : (sin C)f(C,A,B)

X(577) lies on these lines: 2,95   3,6   20,393   22,232   30,53   48,603   69,248   112,376   141,441   160,206   172,1038   184,418   198,478   219,906   220,268   264,401   395,466   396,465

X(577) = inverse of X(216) in the Brocard circle
X(577) = complement of X(317)

Edward Brisse, as cited above X(566), page 7.


X(578) = ORTHOHARMONIC OF X(216)

Trilinears        f(A,B,C) : f(B,C,A) : f(C,A,B), where f(A,B,C) = sin A + cot D/2 cos A,
                        cot D/2 = (a2b2c2 cos A cos B cos C)/[8*(area)3]

Barycentrics  (sin A)f(A,B,C): (sin B)f(B,C,A) : (sin C)f(C,A,B)

X(578) lies on these lines: 2,1092   3,6   4,54   24,51   49,381   156,546   185,378   436,1093

X(578) = inverse of X(389) in the Brocard circle

Edward Brisse, as cited above X(566), page 7.


X(579) = HARMONIC OF X(284)

Trilinears        f(A,B,C) : f(B,C,A) : f(C,A,B), where f(A,B,C) = sin A + cot D/2 cos A,
                        cot D/2 = 4*area*(a + b + c)/(e1 - e2 - 2abc), where
                        e1 = a3 + b3 + c3
                        e2 = a2(b + c) + b2(c + a) + c2(a + b)

Barycentrics  (sin A)f(A,B,C): (sin B)f(B,C,A) : (sin C)f(C,A,B)

X(579) lies on these lines: 1,71   2,7   3,6   19,46   36,48   37,942   40,387   56,219   109,608   165,380   198,218   443,966   474,965   517,1108

X(579) = inverse of X(284) in the Brocard circle

Edward Brisse, as cited above X(566), page 7.


X(580) = ORTHOGONAL OF X(284)

Trilinears        f(A,B,C) : f(B,C,A) : f(C,A,B), where f(A,B,C) = sin A + cot D/2 cos A,
                        cot D/2 = (e1 - e2 - 2abc)/[4*area*(a + b + c)], where e1, e2 are as for X(579)

Barycentrics  (sin A)f(A,B,C): (sin B)f(B,C,A) : (sin C)f(C,A,B)

X(580) lies on these lines: 1,201   2,283   3,6   31,40   34,46   36,54   57,255   162,412   165,601   223,603   238,946   517,595

X(580) = inverse of X(581) in the Brocard circle

Edward Brisse, as cited above X(566), page 7.


X(581) = ORTHOHARMONIC OF X(284)

Trilinears        f(A,B,C) : f(B,C,A) : f(C,A,B), where f(A,B,C) = sin A + cot D/2 cos A,
                        cot D/2 = (2abc - e1 + e2)/[4*area*(a + b + c)], where e1, e2 are as for X(579)

Barycentrics  (sin A)f(A,B,C): (sin B)f(B,C,A) : (sin C)f(C,A,B)

X(581) lies on these lines: 1,4   3,6   35,47   40,42   81,411   84,941   222,1035   936,966&