ISL 2012 G8
Let be a triangle with circumcircle and a line without common points with . Denote by the foot of the perpendicular from the center of to . The side-lines intersect at the points different from . Prove that the circumcircles of the triangles and have a common point different from or are mutually tangent at .
Official text Transcription from NuminaMath olympiads, checked word for word against the official paper. Quoted with source.
Official text: IMO 2012 Shortlist booklet, page 6.
Solutions
Official solution Solution 1 by the IMO Problem Selection Committee
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