smallest no of acute angles by 30 lines
Source: 2014 Belarus TST 2.4
December 30, 2020
combinatorial geometrycombinatoricsacute
Problem Statement
Thirty rays with the origin at the same point are constructed on a plane. Consider all angles between any two of these rays. Let be the number of acute angles among these angles. Find the smallest possible value of .(E. Barabanov)