collinearity wanted, 2 points inside arc are chosen, perpendiculars related
Source: Tuymaada Junior 2004 p3
May 11, 2019
geometrycollinearperpendiculararc
Problem Statement
Point is the center of the circumscribed circle of an acute triangle . A certain circle passes through the points and and intersects sides and of a triangle. On its arc lying inside the triangle, points and are chosen so that the segments and pass through the point . Perpendicular to side and perpendicular to side intersect at . Prove that the points , and lie on the same straight line.