coloring the points
Source: Indonesia IMO 2010 TST, Stage 1, Test 3, Problem 2
November 12, 2009
combinatorics proposedcombinatorics
Problem Statement
Given an equilateral triangle, all points on its sides are colored in one of two given colors. Prove that the is a right-angled triangle such that its three vertices are in the same color and on the sides of the equilateral triangle.
Alhaji Akbar, Jakarta