convex n-gon is divided into triangles by diagonal
Source: 1967 Hungary - Kürschák Competition p2
October 11, 2022
combinatoricscombinatorial geometry
Problem Statement
A convex -gon is divided into triangles by diagonals which do not intersect except at vertices of the n-gon. Each vertex belongs to an odd number of triangles. Show that must be a multiple of .