Tetrahedron

Go to Surface Area or Volume.

Tetrahedron Facts

Notice these interesting things:

 

When we have more than one tetrahedron they are called tetrahedra

 

tetrahedron

The tetrahedron also has a beautiful and unique property ...
all four vertices are the same distance from each other! (thanks Ganesh)

And it is the only Platonic Solid with no parallel faces.

 

tetrahedron irregular

When we say "tetrahedron" we often mean "regular tetrahedron" (in other words all faces are the same size and shape)

But it could be an irregular tetrahedron, like this one:

 

dice tetrahedron

4-Sided Dice? Yes! A tetrahedron that has 4 equal faces has an equal chance of landing on any face.

In fact, you can make fair dice out of all of the Platonic Solids.

 

Make your own Tetrahedron,
cut out the shape and glue it together.
Tetrahedron Model Template

Surface Area and Volume

For a regular tetrahedron:

tetrahedron

Surface Area = √3 × (Edge Length)2

Volume = √212 × (Edge Length)3

Inside a Cube

tetrahedron

Here we see a regular tetrahedron's corners matching neatly with half of the cube's corners.

Can you work out the volume of the cube compared to that tetrahedron?