Polygon

A polygon is a closed, flat shape made entirely from straight sides. Each side meets the next at a vertex. A triangle, quadrilateral and pentagon are polygons because they are closed and have three, four and five straight sides respectively.

In a flat polygon, straight sides meet at vertices. In a solid, an edge is where two faces meet, and a face is a flat surface. For example, a cube has square faces joined along edges, with vertices at the corners.

A polygon is a closed, flat shape whose boundary consists entirely of straight line segments. The segments are its sides, and the points where they meet are its vertices. A triangle has three sides and a quadrilateral has four.