Polyhedra – Colinsmaths

We start with Triangles, Squares and Pentagons. In general we call any of these a Polygon, which means a geometric shape with straight sides. When the sides and the angles of a polygon are equal we call it a Regular Polygon.

A Regular Triangle

Square (a Square is always Regular)

A Regular Pentagon

To make Polyhedra we join regular polygons togther to make solid shapes in 3 dimensions:

Tetrahedron

Hexahedron (Cube)

Octahedron

Dodecahedron

Icosahedron

The next page looks a bit more at The 5 Regular (Platonic) Solids