Definition

A three-dimensional shape that has four flat surfaces, which are called faces.

Example

The tetrahedron is one of the simplest forms of a polyhedron.

Conversation

Have you ever seen a real tetrahedron before?

No, I haven't, but I've read about them in my geometry class.

They're really interesting because they have four faces!

Yeah, I think I would love to build one out of paper.

Synonyms & Antonyms

Root Explanation

Tetrahedron → It is formed from "tetra-" (from Greek "tetra", meaning four) and "hedron" (from Greek "hedra", meaning face or base). The word "tetrahedron" refers to a three-dimensional shape with four faces.

Memory Tip

Imagine a shape with 'four' ('tetra-') 'faces' ('hedron') — that's what a tetrahedron is.

Visually Confused Words