Two circles and midpoints of arcs
Source: Romania EGMO TST 2021 Day 1 P2
November 23, 2022
geometryromania
Problem Statement
Two circles intersect at points . A line passing through intersects the circles again at and . Let and be the midpoints of the arcs \overarc{BC} and \overarc{BD} which do not contain and let be the midpoint of the segment . Prove that and are perpendicular.