Similarity appearing from nowhere
Source: All-Russian 2021/9.4
April 19, 2021
geometry
Problem Statement
Given an acute triangle , point is chosen on the side and a point is chosen on the extension of beyond . It became known that the line through parallel to is tangent to the circumcircle of . Prove that one of the tangents from to the circumcircle of cuts the angle in such a way that a triangle similar to is formed.