What does a pentadecagon look like?

Answer 1

In geometry, a pentadecagon (or pentakaidecagon) is any 15-sided, 15-angled, polygon. A regular pentadecagon has interior angles of 156°, and with a side length a, has an area given by:

A= 15/4 * a²* cot π/15

= (15a²)/8 (√3 + √15+ √2* √(5+√5))

≈ 17.6424 a²