Triskaidecagon

In Geometry, a triskaidecagon (or tridecagon) is a polygon with 13 sides and angles. The measure of each internal angle of a regular triskaidecagon is approximately 152.308 degrees, and the area with side length a is given by

<math>A = \frac{13}{4}a^2 \cot \frac{\pi}{13} \simeq 13.1858 a^2.</math>

A regular triskaidecagon is not constructible with compass and straightedge. However, it is constructible using a Neusis construction.

External links

• Eric W. Weisstein, Tridecagon at MathWorld.