X153

REFLECTION OF X20 IN X100

X153 is the reflection of X20 in X100.
< A B C >: Reference Triangle △ABC [ A B ]: Sideline AB (Base c = 1) [ B C ]: Sideline BC (Side a) [ C A ]: Sideline CA (Side b) { 20, 100 }: Central Line L(20, 100) { 7, 80 }: Central Line L(7, 80) { 2, 104 }: Central Line L(2, 104) { 4, 145 }: Central Line L(4, 145) { 11, 388 }: Central Line L(11, 388) A = Vertex A (0.0000, 0.0000) B = Vertex B (1.0000, 0.0000) C = Vertex C (0.6122, 0.5999) X_20 = DE LONGCHAMPS POINT (0.3878, -0.1916) X_100 = ANTICOMPLEMENT OF FEUERBACH POINT (0.1429, 0.4666) X_7 = GERGONNE POINT (0.5903, 0.2769) X_80 = REFLECTION OF INCENTER IN FEUERBACH POINT (0.8980, -0.1000) X_2 = CENTROID (0.5374, 0.2000) X_104 = ANTIPODE OF X(100) (0.8571, -0.2624) X_4 = ORTHOCENTER (0.6122, 0.3958) X_145 = ANTICOMPLEMENT OF NAGEL POINT (0.6735, 0.3333) X_11 = FEUERBACH POINT (0.7347, 0.0667) X_388 = ∩X(7)X(8) (0.5790, 0.2635) X_153 = REFLECTION OF X(20) IN X(100) (-0.1020, 1.1248) A B C X20 X100 X7 X80 X2 X104 X4 X145 X11 X388 X153 (a, b, c) = (5, 6, 7) | AB = 1

X153 (REFLECTION OF X20 IN X100) constructed on acute reference triangle \((a, b, c) = (5, 6, 7)\) with unit baseline AB = \(1\).

Constructed Elements

Trilinears: \(f(a,b,c) : f(b,c,a) : f(c,a,b)\), where \(f(a,b,c) = (by + cz - ax)/a\), where \(x : y : z\) = X104
Barycentrics: \(a^{7} - a^{6} (b + c) - a^{5} (b^{2} - 7 b c + c^{2}) + a^{4} (b + c) (b^{2} - 6 b c + c^{2}) - a^{3} (b^{4} + 2 b^{3} c - 10 b^{2} c^{2} + 2 b c^{3} + c^{4}) + a^{2} (b - c)^{2} (b + c) (b^{2} + 6 b c + c^{2}) + a (b^{2} - c^{2})^{2} (b^{2} - 5 b c + c^{2}) - (b - c)^{4} (b + c)^{3} : :\)
Search Value (6, 9, 13): \(-14.037672929368\)

X153 lies on the anticomplementary circle.

▸ Incident Central Lines6 lines

{2, 104}, {4, 145}, {7, 80}, {11, 388}, {20, 100}, {515, 908}

▸ Functional Relations4 relations

Notes

Let T be the P-Brocard triangle for any P on line X1X3. Let OA be the circle centered at the A-vertex of T and passing through A; define OB and OC cyclically. X153 is the radical center of OA, OB, OC. (Randy Hutson, August 30, 2020)