LX and BC meet at given circle, perpendularity wanted
Source: 2019 Nigerian Senior Mathematics Olympiad Round 4 (final) problem 2
September 9, 2019
geometrymidpointperpendicularcircle
Problem Statement
Let be the midpoints of repectively on a given triangle . Let be a circle passing through and tangent to the circumcircle of , say at . Suppose that and meet at . Show that is perpendicular to .