IMO 1987 LL MOR45

Let us consider a variable polygon with 2n sides (n \inN) in a

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IMO 1987 LL MOR45

Origin: MOR

Problem

Let us consider a variable polygon with 2n sides (n \inN) in a fixed circle such that 2n −1 of its sides pass through 2n −1 fixed points lying on a straight line ∆. Prove that the last side also passes through a fixed point lying on ∆.