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Coins on the table form regular polygons

Source: BWM Germany Round 1, 2015 - Problem 1

April 8, 2015
geometrypolygonbundeswettbewerbGermany

Problem Statement

Twelve 1-Euro-coins are laid flat on a table, such that their midpoints form a regular 1212-gon. Adjacent coins are tangent to each other. Prove that it is possible to put another seven such coins into the interior of the ring of the twelve coins.