A Tridecagon is a 13-sided polygon with 13 angles.
Petrie polygons
The regular tridecagon is the Petrie polygon for a number of higher-dimensional polytopes, projected in a skew orthogonal projection, including from the A12, 12-simplex family:
| A12 |  12-simplex |
 Rectified 12-simplex |
 Birectified 12-simplex |
 trirectified 12-simplex |
 quadrirectified 12-simplex |
 quintirectified 12-simplex |
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