3 of 13 points on circle of r=1 form a triangle with area <13
Source: 2020 New Zealand MO Round 2 p3 NZMO
September 22, 2021
geometrycombinatorial geometrycombinatorics
Problem Statement
There are marked points on the circumference of a circle with radius . Prove that we can choose three of the marked points which form a triangle with area less than .