MathDB
circumcenter of ABC = incenter of ABD(2019 Novosibirsk Oral Geo Oly 9.2)

Source:

April 28, 2021
geometryincenter

Problem Statement

An angle bisector ADAD was drawn in triangle ABCABC. It turned out that the center of the inscribed circle of triangle ABCABC coincides with the center of the inscribed circle of triangle ABDABD. Find the angles of the original triangle.