Geometry · Quadrilaterals & Polygons

Polygon

HSG-CO.C.11

Definition

A closed two-dimensional figure formed by three or more straight sides.

Examples

  • A pentagon (5 sides), hexagon (6 sides), and octagon (8 sides) are all polygons.
  • A polygon must be a closed figure — every side must connect.

Key rule

A polygon is made only of straight line segments, with no gaps or curves.

Memory hook

Closed shape, straight sides.