MathDB
ABC has an angle of 60^o if IO = IH

Source: Canada Repêchage 2024/7b CMOQR

March 25, 2024
geometryequal segments

Problem Statement

In triangle ABCABC, let II be the incentre, OO be the circumcentre, and HH be the orthocentre. It is given that IO=IHIO = IH. Show that one of the angles of triangle ABCABC must be equal to 6060 degrees.