Diagonals are concurrent triplewise
Source: 2021 MEMO T-4
September 5, 2021
regular polygoncombinatoricsmemoMEMO 2021
Problem Statement
Let be a positive integer. Prove that in a regular -gon, we can draw diagonals with pairwise distinct ends and partition the drawn diagonals into triplets so that:[*] the diagonals in each triplet intersect in one interior point of the polygon and
[*] all these intersection points are distinct.