X1489¶
3rd STEVANOVIC POINT
X1489 (3rd STEVANOVIC POINT) constructed on acute reference triangle \((a, b, c) = (5, 6, 7)\) with unit baseline AB = \(1\).¶
Constructed Elements
Derived Triangle: Medial Triangle △MaMbMc — vertices Ma, Mb, Mc (Formed by the midpoints of sides BC, CA, AB)
Central Lines: {2, 1143}
Related Centers: X2 (CENTROID), X1143 (2nd MALFATTI-RABINOWITZ POINT)
Trilinears: \(f(A,B,C) : f(B,C,A) : f(C,A,B)\), where \(f(A,B,C) = (\csc A)[1 - \cos(A/2) - \sin(A/2)]\)
Barycentrics: \(1 - \cos(A/2) - \sin(A/2) : 1 - \cos(B/2) - \sin(B/2) : 1 - \cos(C/2) - \sin(C/2)\)
Search Value (6, 9, 13): \(1.775305425860\)
Functional Relations3 relations
Notes¶
Let U be the A-excenter of triangle ABC; let A' be the incenter of triangle UBC, and define B', C' cyclically. Let I be the incenter of ABC, let A″ be the incenter of triangle IBC, and define B″, C″ cyclically. Let X = A'A″∩BC, and define Y, Z cyclically. Then AX, BY, CZ concur in X1489. (Milorad R. Stevanovic, Hyacinthos #7185, 5/21/03. See also X1130 and X1489.)