Maths Dictionary

Icosahedron

An icosahedron is a 3D solid shape (polyhedron) that has 20 triangular faces, 30 edges, and 12 vertices (corners).

All the faces are equilateral triangles in a regular icosahedron.

It is one of the five Platonic solids, which are special shapes where all faces, edges, and angles are the same.

The name comes from Greek: “eíkosi” means twenty, and “hédra” means face.

Fun fact:
The icosahedron is often used in gaming as the 20-sided dice (D20).