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there exists a point belonging to all the sets-ILL1990 SWE3

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September 19, 2010
geometry theoremsgeometry

Problem Statement

Let A1,A2,,An(n4)A_1, A_2, \ldots, A_n (n \geq 4) be nn convex sets in plane. Knowing that every three convex sets have a common point. Prove that there exists a point belonging to all the sets.