ASU 518 All Soviet Union 1990 n^2 equilateral triangle of side 1, acute in path
Source:
August 14, 2019
equilateralsacutecombinatorial geometrycombinatorics
Problem Statement
An equilateral triangle of side is divided into equilateral triangles of side . A path is drawn along the sides of the triangles which passes through each vertex just once. Prove that the path makes an acute angle at at least vertices.