r1870	circumcircle, perspective, isogonal points, point X(858)
r1872	circumcircle, perspective, orthic triangle
r1877	isogonal points
r1889	circumcenter, circumcircle
r1895	Feuerbach point
r1912	orthologic triangles, parallelogic triangles
r1913	orthocenter, circumcenter, ninecenter, Euler line
r1985	Euler line, Jerabek hyperbola
r1996	orthocenter, Euler line
r1998	circumcenter, orthologic triangles, Kosnita point, point X(52)
r2009	orthocenter, circumcenter, ninecenter, Euler line, excenters
r2022	incenter, Nagel point
r2023	circumcenter, incenter, ninecenter, altitude feet, altitudes, point X(52)
r2024	altitude feet, altitudes, Gob point
r2027	circumcenter, incenter, incentric triangle, point X(100), isogonal of the infinite point, radical center
r2056	altitude feet, orthocenter, isogonal points, Euler line, circumcircle
r2070

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