A dodecagon has 12 sides.

Quick Scoop: Dodecagon Basics

  • A dodecagon is a flat polygon with 12 sides, 12 angles, and 12 vertices.
  • The name comes from Greek: “dodeka” meaning 12 and “gonia/gōnon” meaning angle.
  • In regular form, all 12 sides and all 12 angles are equal.

Mini FAQ (Fast Facts)

  • How many sides? 12 sides.
  • How many interior angles? 12 interior angles.
  • Sum of interior angles? 1800°.
  • Each exterior angle (regular)? 30°.

Think of it as the next step after a decagon (10 sides) and hendecagon/undecagon (11 sides): the dodecagon is simply the 12‑sided member of the polygon “family.”

Information gathered from public forums or data available on the internet and portrayed here.