X325

X2-HIRST INVERSE OF X69

< 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) { 2, 6 }: Centroid–Symmedian Line { 5, 76 }: Central Line L(5, 76) { 30, 99 }: Central Line L(30, 99) { 22, 160 }: Central Line L(22, 160) { 3, 315 }: Central Line L(3, 315) { 25, 317 }: Central Line L(25, 317) A = Vertex A (0.0000, 0.0000) B = Vertex B (1.0000, 0.0000) C = Vertex C (0.6122, 0.5999) X_2 = CENTROID (0.5374, 0.2000) X_6 = SYMMEDIAN POINT (LEMOINE POINT, GREBE POINT) (0.6000, 0.2672) X_5 = NINE-POINT CENTER (0.5561, 0.2489) X_76 = 3rd BROCARD POINT (0.4567, 0.1388) X_30 = EULER INFINITY POINT (0.7469, 0.7481) X_99 = STEINER POINT (0.1109, 0.4322) X_22 = EXETER POINT (0.4143, -0.1221) X_160 = -OF-TANGENTIAL-TRIANGLE (0.4841, -0.0647) X_3 = CIRCUMCENTER (0.5000, 0.1021) X_315 = ISOTOMIC CONJUGATE OF X(66) (0.3323, -0.0666) X_25 = HOMOTHETIC CENTER OF ORTHIC AND TANGENTIAL TRIANGLES (0.6329, 0.4497) X_317 = ISOTOMIC CONJUGATE OF X(68) (0.6796, 0.5070) X_325 = -HIRST INVERSE OF X(69) (-0.3370, -0.7398) A B C X2 X6 X5 X76 X30 X99 X22 X160 X3 X315 X25 X317 X325 (a, b, c) = (5, 6, 7) | AB = 1

X325 (X2-HIRST INVERSE OF X69) constructed on acute reference triangle \((a, b, c) = (5, 6, 7)\) with unit baseline AB = \(1\).

Constructed Elements

Trilinears: \(\csc^{2} A : :\)
Barycentrics: \(\cot A - \tan \omega : :\)
Search Value (6, 9, 13): \(7.504301653149\)
▸ Alternate Coordinates2 forms
  • Trilinears: \(bc(b^{4} + c^{4} - a^{2}b^{2} - a^{2}c^{2}) : :\)

  • Barycentrics: \(b^{4} + c^{4} - a^{2}b^{2} - a^{2}c^{2} : :\)

X325 lies on the Simson quartic Q101.

▸ Incident Central Lines75 lines

{2, 6}, {3, 315}, {4, 1975}, {5, 76}, {11, 350}, {12, 1909}, {20, 6337}, {22, 160}, {23, 3447}, {25, 317}, {30, 99}, {32, 3788}, {39, 626}, {51, 4121}, {74, 2855}, {75, 2886}, {95, 1799}, {98, 2065}, {100, 2856}, {110, 2857}, {111, 2858}, {114, 511}, {115, 538}, {140, 1078}, {147, 1503}, {187, 620}, {194, 5025}, {232, 297}, {250, 340}, {253, 6340}, {264, 305}, {274, 442}, {290, 3978}, {310, 3136}, {311, 1238}, {320, 1447}, {332, 2893}, {339, 1236}, {383, 622}, {441, 2966}, {523, 684}, {532, 6108}, {533, 6109}, {542, 5939}, {621, 1080}, {623, 6115}, {624, 6114}, {631, 3785}, {637, 6289}, {638, 6290}, {639, 3103}, {640, 3102}, {671, 5503}, {672, 4766}, {698, 1916}, {732, 2023}, {740, 5988}, {758, 5977}, {868, 2396}, {892, 1494}, {1235, 1594}, {1329, 6377}, {1368, 6375}, {1444, 4220}, {1506, 3934}, {2071, 5866}, {2482, 3849}, {3233, 6148}, {3734, 5475}, {3814, 6382}, {3829, 4479}, {3847, 4357}, {3932, 4518}, {5149, 5162}, {5965, 6036}

▸ Functional Relations23 relations

Notes

Let La be the line through A parallel to the Lemoine axis, and define Lb and Lc cyclically. Let Ma be the reflection of BC in La, and define Mb and Mc cyclically. Let A' = Mb∩Mc, and define B' and C' cyclically. The triangle A'B'C' is inversely similar to, and 3 times the size of, ABC. Let A″B″C″ be the reflection of A'B'C' in the Lemoine axis. The triangle A″B″C″ is homothetic to ABC, with center of homothety X325; see Hyacinthos #16741/16782, Sep 2008. (Randy Hutson, November 30, 2015)