What is a 12-sided figure called?

A 12-sided polygon is called a dodecagon. A polygon is any closed figure with 3 or more sides and angles. Every polygon with 3 to 20 sides has a name. Polygons with 30, 40, 50, 60, 70, 80, 90, and 100 sides have specific names as well.

Polygons with 3 to 12 sides, excluding 9 and 11, have commonly used names. These are triangles (3), quadrilaterals (4), pentagons (5), hexagons (6), heptagons (7), octagons (8), decagons (10), and dodecagons (12), respectively. Polygons with more than twelve sides have specific names but are less commonly used.