circumcenter of ABC lies on the bisector of the original angle
Source: Tournament of Towns Spring 1998 Seniors O p5
May 11, 2020
geometryangle bisectorreflectioncircle
Problem Statement
A circle with center is inscribed in an angle. Let be the reflection of across one side of the angle. Tangents to the circle from intersect the other side of the angle at points and . Prove that the circumcenter of triangle lies on the bisector of the original angle. (I.Sharygin)