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fixed incircle and circumcircle

Source: Iran 3rd round 2011-geometry exam-p4

September 6, 2011
geometrycircumcircleincentergeometric transformationreflectionradical axisgeometry proposed

Problem Statement

A variant triangle has fixed incircle and circumcircle. Prove that the radical center of its three excircles lies on a fixed circle and the circle's center is the midpoint of the line joining circumcenter and incenter.
proposed by Masoud Nourbakhsh