C5

Part of 2016 IMO Shortlist

Problems(1)

Maximize non-intersecting/perpendicular diagonals!

Source: 2016 IMO Shortlist C5

n \geq 3

be a positive integer. Find the maximum number of diagonals in a regular

n

-gon one can select, so that any two of them do not intersect in the interior or they are perpendicular to each other.

combinatoricsIMO ShortlistExtremal combinatorics