A regular $100$-gon was cut into several parallelograms and two triangles. Prove that these triangles are congruent.
Problem
Source: 44th International Tournament of Towns, Senior A-Level P4, Spring 2023
Tags: geometry
Source: 44th International Tournament of Towns, Senior A-Level P4, Spring 2023
Tags: geometry
A regular $100$-gon was cut into several parallelograms and two triangles. Prove that these triangles are congruent.