ISL 2022 G1
Let be a convex pentagon such that . Assume there is a point inside with and . Let lines and intersect line at points and , respectively, and let lines and intersect line at points and , respectively. Assume that points and respectively, are collinear and occur on their lines in this order. Prove that the points are concyclic. (Slovakia)
Official text Transcription from NuminaMath olympiads, checked word for word against the official paper. Quoted with source.
Official text: IMO 2022 Shortlist booklet, page 8.
Solutions
Official solution Solution 1 by the IMO Problem Selection Committee
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