r541	orthic triangle, extouch triangle, symmedian point
r774	orthocenter, circumcenter, ninecenter, altitudes, Jerabek hyperbola, Kosnita point, point X(389)
r775	orthocenter, circumcenter, altitudes, cevian triangle
r851	orthiac triangles, medians
r1065	circumcenter, orthocenter, orthologic triangles, altitude feet