r337	orthic triangle, ninecenter, perspective
r619	circumcircle, orthopole, circumcenter
r739	incenter, excentral triangle, orthocenter, circumcenter, Bevan point, Mittenpunkt, point X(64), point X(84)
r1213	altitude feet, radical center
r1253	orthocenter, altimedial triangles, complement
r1455	ninecenter, symmedian point, point X(155)
r1561	orthocenter, excenters, excentral triangle
r1562	pedal triangle, pedal circle, orthocenter
r1579	altitudes
r1637	circlecevian triangle, orthocenter