Tridecagon

Template:Regular polygon db A tridecagon or triskaidecagon or trisdecagon or 13-gon is a shape with 13 sides and 13 corners.

Regular tridecagon

All sides of a regular tridecagon are the same length. Each corner is 147.27°. All corners added together equal 6840°.

Area

The amount of space a regular tridecagon takes up is

$A=\frac{13}{4}{a}^2\cot \frac{\pi }{13}\simeq 13.1858a^2.$

a is the length of one of its sides.

Numismatic use

The regular tridecagon is used as the shape of the Czech 20 korun coin.

Related pages

• Triskaidekaphobia

Other websites

• Template:MathWorld