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Prove that points $M, N$ and $P$ are collinear.

Source: Moldova TST 1995

August 8, 2023
geometry

Problem Statement

Each pair of three circles have the common chords AA1,BB1AA_1, BB_1 and CC1CC_1{} such that lines ABAB{} and A1B1A_1B_1 intersect in point MM{}, BCBC and B1C1B_1C_1 intersect in point NN{}, CACA{} and C1A1C_1A_1 intersect in point PP{}. Prove that points M,NM, N and PP are collinear.