MathDB
circumcenter is midpoint of segment of incenter-orthocenter of another triangle

Source: Sharygin 2006 X-XI CR 19

August 24, 2019
geometryincentermidpointsperpendicularCircumcenterorthocenter

Problem Statement

Through the midpoints of the sides of the triangle TT, straight lines are drawn perpendicular to the bisectors of the opposite angles of the triangle. These lines formed a triangle T1T_1. Prove that the center of the circle circumscribed about T1T_1 is in the midpoint of the segment formed by the center of the inscribed circle and the intersection point of the heights of triangle TT.