MathDB
Covering an n-polygon

Source: Indian postal coaching 2008

December 21, 2008
geometrycircumcircleinductionextremal principlecombinatorics unsolvedcombinatorics

Problem Statement

Let A1A2...An A_1A_2...A_n be a convex polygon. Show that there exists an index j j such that the circum-circle of the triangle A_j A_{j \plus{} 1} A_{j \plus{} 2} covers the polygon (here indices are read modulo n).