Regular hexagon combo
Source: Polish MO Second round 2024 P4
February 10, 2024
combinatorics
Problem Statement
Let be a positive integer. A regular hexagon with side length is partitioned into equilateral triangles with side length . The hexagon is covered by rhombuses with internal angles and such that each rhombus covers exactly two triangles and every triangle is covered by exactly one rhombus. Show that the diagonal divides in half exactly rhombuses.