X1658

CIRCUMCENTER OF KOSNITA TRIANGLE

The vertices of the Kosnita triangle are the circumcenters of the triangles BOC, COA, AOB, where O is the circumcenter, X3. (Darij Grinberg, 8/24/03)
< A B C >: Reference Triangle △ABC < O_A O_B O_C >: Kosnita Triangle △O_A O_B O_C [ A B ]: Sideline AB (Base c = 1) [ B C ]: Sideline BC (Side a) [ C A ]: Sideline CA (Side b) circumcircle_of_kosnita: Circumcircle of kosnita [ O_A X_1658 ]: Line [ O_A X_1658 ] [ O_B X_1658 ]: Line [ O_B X_1658 ] [ O_C X_1658 ]: Line [ O_C X_1658 ] { 2, 3 }: Euler Line { 54, 568 }: Central Line L(54, 568) { 143, 578 }: Central Line L(143, 578) { 569, 973 }: Central Line L(569, 973) { 1147, 1154 }: Central Line L(1147, 1154) A = Vertex A (0.0000, 0.0000) B = Vertex B (1.0000, 0.0000) C = Vertex C (0.6122, 0.5999) X_3 = CIRCUMCENTER (0.5000, 0.1021) O_A = Kosnita Circumcenter O_A (0.8000, 0.2960) O_B = Kosnita Circumcenter O_B (0.1711, 0.4378) O_C = Kosnita Circumcenter O_C (0.5000, -1.1737) X_2 = CENTROID (0.5374, 0.2000) X_54 = KOSNITA POINT (0.5880, 0.2176) X_568 = ORTHOHARMONIC OF X(50) (0.6437, 0.3393) X_143 = NINE-POINT CENTER OF ORTHIC TRIANGLE (0.6358, 0.3534) X_578 = ORTHOHARMONIC OF X(216) (0.5933, 0.2561) X_569 = HARMONIC OF X(52) (0.5651, 0.2096) X_973 = 1st EHRMANN POINT (0.6138, 0.3246) X_1147 = ISOGONAL CONJUGATE OF X(847) (0.8329, 0.3027) X_1154 = ISOGONAL CONJUGATE OF X(1141) (0.8932, 0.6667) X_1658 = CIRCUMCENTER OF KOSNITA TRIANGLE (0.3191, -0.3713) A B C X3 OA OB OC X2 X54 X568 X143 X578 X569 X973 X1147 X1154 X1658 (a, b, c) = (5, 6, 7) | AB = 1

X1658 (CIRCUMCENTER OF KOSNITA TRIANGLE) constructed on acute reference triangle \((a, b, c) = (5, 6, 7)\) with unit baseline AB = \(1\).

Constructed Elements

  • Derived Triangle: Kosnita Triangle △OAOBOC — vertices OA, OB, OC (Circumcenters of △BOC, △COA, △AOB where O = X3)

  • Circle: circumcircleofkosnita — Centered at X1658

  • Concurrence Lines: OA–X1658, OB–X1658, OC–X1658 concurring at X1658

  • Central Lines: {2, 3} (Euler line)

  • Related Centers: X3 (CIRCUMCENTER), X2 (CENTROID)

Trilinears: \(\cos(B - C) + 4 \cos 2A \cos B \cos C : :\) (Nikolaos Dergiades, Hyacinthos 7752)
Search Value (6, 9, 13): \(2.332793429859\)
▸ Incident Central Lines6 lines

{2, 3}, {54, 568}, {143, 578}, {569, 973}, {1092, 1511}, {1147, 1154}

▸ Functional Relations1 relation

Notes

As a point on the Euler line, X1658 has Shinagawa coefficients \((E + 8F, -3E - 8F)\).

Let La be the polar of X4 wrt the circle centered at A and passing through X3, and define Lb, Lc cyclically. (Note: X4 is the perspector of any circle centered at a vertex of ABC.) Let A″ = Lb∩Lc, and define B″ and C″ cyclically. Triangle A″B″C″ is homothetic to ABC, and its nine-point center is X1658. (Randy Hutson, July 20, 2016)