polygon with 13 sides

A tridecagon or trikaidecagon or triskaidecagon or trisdecagon or 13-gon is a shape with 13 sides and 13 corners.

Regular tridecagon
A regular tridecagon
TypeRegular polygon
Edges and vertices13
Schläfli symbol{13}
Coxeter diagramCDel node 1.pngCDel 13.pngCDel node.png
Symmetry groupDihedral (D13), order 2×13
Internal angle (degrees)≈152.308°
Dual polygonSelf
PropertiesConvex, cyclic, equilateral, isogonal, isotoxal

Regular tridecagonEdit

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


The amount of space a regular tridecagon takes up is


a is the length of one of its sides.

Numismatic useEdit

The regular tridecagon is used as the shape of the Czech 20 korun coin.[1]


Related pagesEdit


  1. Colin R. Bruce, II, George Cuhaj, and Thomas Michael, 2007 Standard Catalog of World Coins, Krause Publications, 2006, ISBN 0896894290, p. 81.

Other websitesEdit