Junior Combinatorics
Source: 2015 JBMO TST - Macedonia, Problem 5
December 31, 2015
polygonColoringcombinatorics2015
Problem Statement
and are two identical convex polygons, each with an area of . The polygon is divided into polygons , while is divided into polygons . Each of these smaller polygons has a positive area. Furthermore, and are colored in distinct colors, such that and are differently colored for every distinct and and and are also differently colored for every distinct and . After and overlap, we calculate the sum of the areas with the same colors. Prove that we can color the polygons such that this sum is at least .