MathDB
Maximum number of obtuse angles

Source: 2008 Bulgarian Autumn Math Competition, Problem 8.4

March 18, 2022
GeoemtrycombinatoricsObtuse triangle

Problem Statement

Let MM be a set of 9999 different rays with a common end point in a plane. It's known that two of those rays form an obtuse angle, which has no other rays of MM inside in. What is the maximum number of obtuse angles formed by two rays in MM?
Back to ProblemsView on AoPS