r290	circumcircle, inverse points, altitude feet, perspective
r291	circumcircle, inverse points, point X(403)
r352	circumcenter, orthic triangle, homothetic triangles
d	Prasolov point
r711	ninecircle, orthocentroidal circle, point X(186),i nverse points
r750	perspective, orthocenter, orthic triangle
r1565	orthocenter, altitudes, altitude feet
r1570	isogonal points, circumcevian triangle, circumcenter, orthocenter, De Longchamps point
r1637	circlecevian triangle, circumcenter
r1638	circumcevian triangle, perspective, orthocenter, circumcenter
r1787	circumcircle, orthocenter, circumcevian triangle, symmedian point, tripolar, cevian product