Sawayama - Thebault's theorem. Level: High School, SAT Prep, College geometry

The figure shows a triangle ABC, D is the incenter of triangle ABC. Point E is taken on side AC, G and F are the centers of circles that touch BE, AC and the circumcircle of triangle ABC. Prove that G, D, and F are collinear.


 

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Last updated: March 1, 2008