Decagon
| Regular decagon | |
|---|---|
A regular decagon | |
| Type | Regular polygon |
| Edges and vertices | 10 |
| Schläfli symbol | {10}, t{5} |
| Coxeter–Dynkin diagrams | |
| Symmetry group | Dihedral (D10), order 2×10 |
| Internal angle (degrees) | 144° |
| Properties | Convex, cyclic, equilateral, isogonal, isotoxal |
| Dual polygon | Self |
In geometry, a decagon (from the Greek δέκα déka and γωνία gonía, "ten angles") is a ten-sided polygon or 10-gon. The total sum of the interior angles of a simple decagon is 1440°.