Convex $n$-gon $P$, where $n> 3$, is cut into equal triangles by diagonals that do not intersect inside it. What are the possible values of $n$ if the $n$-gon is cyclic?
Problem
Source: 2010 Oral Moscow Geometry Olympiad grades 10-11 p1
Tags: geometry, combinatorial geometry, combinatorics, Cyclic, polygon, convex polygon