Prove that the lines $BP$ and $CQ$ are perpendicular.
Source: Moldova TST 2022
April 1, 2022
geometry
Problem Statement
Let be a point outside of the circle . Tangents from touch in points and . Point , collinear with and , is between and , such that the circumcircle of triangle intersects again in point . Point is on the segment , such that . Prove that the lines and are perpendicular.