X3580¶
INTERSECTION OF LINES X2X_6 AND X30X_74
X3580 (INTERSECTION OF LINES X2X_6 AND X30X_74) constructed on acute reference triangle \((a, b, c) = (5, 6, 7)\) with unit baseline AB = \(1\).¶
Constructed Elements
Central Lines: {2, 6}, {24, 68}
Related Centers: X2 (CENTROID), X6 (SYMMEDIAN POINT), X24 (PERSPECTOR OF ABC AND ORTHIC-OF-ORTHIC TRIANGLE), X68 (PRASOLOV POINT)
Alternate Coordinates1 form
Trilinears: \((\csc A)(1 + \cos 2B + \cos 2C) : :\)
X3580 lies on the Walsmith rectangular hyperbola.
Incident Central Lines24 lines
Functional Relations15 relations
X3580 = midpoint of Xi and Xj for these (i,j): (23, 3448), (265, 3581)
X3580 = reflection of Xi in Xj for these (i,j): (110, 468), (146, 1514), (858, 125)
X3580 = isotomic conjugate of X2986
X3580 = X340-Ceva conjugate of X30
X3580 = X3003-cross conjugate of X403
X3580 = crosspoint of Xi and Xj for these (i,j): (2, 94), (76, 1494)
X3580 = crosssum of Xi and Xj for these (i,j): (6, 50), (32, 1495), (647, 2088)
X3580 = crossdifference of every pair of points on the line X184X512
X3580 = crosspoint of X6 and X2931 wrt both the excentral and tangential triangles
X3580 = pole wrt polar circle of trilinear polar of X1300
X3580 = X48-isoconjugate (polar conjugate) of X1300
Notes¶
Let La, Lb, Lc be the lines through A, B, C, resp. parallel to the orthic axis. Let Ma, Mb, Mc be the reflections of BC, CA, AB in La, Lb, Lc, resp. Let A' = Mb∩Mc, and define B' and C' cyclically. 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 orthic axis. The triangle A″B″C″ is homothetic to ABC, and its centroid is X3580; see Hyacinthos #16741/16782, Sep 2008. (Randy Hutson, March 25, 2016)