Tridecagon

In geometry, a tridecagon or triskaidecagon or 13-gon is a thirteen-sided polygon. Wikipedia

Dual polygon: Self

Edges and vertices: 13

Internal angle (degrees): ≈152.308°

Properties: Convex, cyclic, equilateral, isogonal, isotoxal

Symmetry group: Dihedral (D₁₃), order 2×13