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Rigby Points

The Perspective Centers of the Tangential and Contact Triangles of the inner and outer Soddy Points. The Rigby points are given by

{\it Ri}=I+{\textstyle{4\over 3}}{\it Ge}

{\it Ri}'=I-{\textstyle{4\over 3}}{\it Ge},

where $I$ is the Incenter and Ge is the Gergonne Point.

See also Contact Triangle, Gergonne Point, Griffiths Points, Incenter, Oldknow Points, Soddy Points, Tangential Triangle


Oldknow, A. ``The Euler-Gergonne-Soddy Triangle of a Triangle.'' Amer. Math. Monthly 103, 319-329, 1996.

© 1996-9 Eric W. Weisstein