MathDB
Unexpectedly difficult combo geo

Source: Mongolian Mathematical Olympiad 2024 P2

April 12, 2024
combinatoricsgeometryExtremal

Problem Statement

We call a triangle consisting of three vertices of a pentagon big if it's area is larger than half of the pentagon's area. Find the maximum number of big triangles that can be in a convex pentagon.
Proposed by Gonchigdorj Sandag