de Longchamps point

In geometry, the de Longchamps point of a triangle is the reflection of its orthocenter about its circumcenter.[1] It is listed as X(20) in the Encyclopedia of Triangle Centers. Its trilinear coordinates are

\displaystyle\cos A - \cos B \cos C�: \cos B - \cos C \cos A�: \cos C - \cos A \cos B

The point is collinear with the orthocenter and circumcenter.[1]

See also

Notes

  1. ^ a b Weisstein, Eric W. "de Longchamps Point." From MathWorld--A Wolfram Web Resource. http://mathworld.wolfram.com/deLongchampsPoint.html