ISL 2019 G1
Let be a triangle. Circle passes through , meets segments and again at points and respectively, and intersects segment at and such that lies between and . The tangent to circle at and the tangent to circle at meet at point . Suppose that points and are distinct. Prove that line is parallel to . (Nigeria)
Official text Transcription from NuminaMath olympiads, checked word for word against the official paper. Quoted with source.
Official text: IMO 2019 Shortlist booklet, page 10.
Solutions
Official solution Solution 1 by the IMO Problem Selection Committee
The terms of the source let olymmath link to this solution but not copy it. Read the solution (IMO official site).