A pentadecagon is a polygon with 15 sides and 15 vertices.
A regular pentadecagon is a polygon with 15 equal sides and angles.
Angles of the Pentadecagon
The sum of interior angles of a pentadecagon = (15 − 2) · 180° = 2,340°
The value of an interior angle of a regular pentadecagon is: 2,340º : 15 = 156º
The central angle of a regular pentadecagon measures: 360º : 15 = 24º
Diagonals of the Pentadecagon
The number of diagonals in a regular pentadecagon = 15 · (15 − 3) : 2 = 90.
Perimeter of a Regular Pentadecagon
Perimeter = 15 · l
Area of a Regular Pentadecagon