# Torus

Torus Facts

**Notice these interesting things:**

- It can be made by revolving a

small circle along a line made

by a bigger circle. - It has no edges or vertices
- It is
**not**a polyhedron

*.*

Torus in the Sky

Torus in the Sky

The Torus is such a beautiful solid,

this one would be fun at the beach !

## Volume and Surface Area

Surface Area = 4 × **π**^{2} × R × r

Volume = 2 × *π*^{2} × R × r^{2}

*Note: Area and volume formulas only work when the torus has a hole!*

And did you know that

*Torus*was the Latin word for a

**cushion**?

(This is not a *real* roman cushion, just an illustration I made)

When we have more than one torus they are called

**tori**## More Torus Images

As the small radius (**r**) gets larger and larger, the torus goes from looking like a

*to a*

**Tire**

**Donut:**