P2- first combinatorics exam of 2017 Iran MO 3rd round
Source: 2017 Iran MO 3rd round, first combinatorics exam P2
September 12, 2017
Irancombinatorics
Problem Statement
An angle is considered as a point and two rays coming out of it.
Find the largest value on such that it is possible to place degree angles on the plane in a way that any pair of these angles have exactly intersection points.