An arrangement in three-dimensional space of *n* congruent cubes joined to one another by at least one of their faces.

- A polycube formed by joining 2 cubes is called a
*dicube*.
- Polycubes formed by joining 3 cubes are called
*tricubes*. There are 2 tricubes.
- Polycubes formed by joining 4 cubes are called
*tetracubes*. There are 8 tetracubes.
- Polycubes formed by joining 5 cubes are called
*pentacubes*. There are 29 pentacubes.
- Polycubes formed by joining 6 cubes are called
*hexacubes*. There are 166 hexacubes.

### Example

This is a pentacube:

This photo shows a pyramidal arrangement of 166 hexacubes.

This structure was designed by A. Clarke and assembled by Pierre Mathieu.