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$R, B$ and $R'$ are collinear

Source: 39-th Vietnamese Mathematical Olympiad 2001

March 19, 2007
ratiogeometrypower of a pointradical axisperpendicular bisectorgeometry unsolved

Problem Statement

A circle center OO meets a circle center OO' at AA and B.B. The line TTTT' touches the first circle at TT and the second at TT'. The perpendiculars from TT and TT' meet the line OOOO' at SS and SS'. The ray ASAS meets the first circle again at RR, and the ray ASAS' meets the second circle again at RR'. Show that R,BR, B and RR' are collinear.