# Cubic identity 1

Objective
 To verify $(a+b)^3 = a^3+3a^2b+3ab^2+b^3$ using unit cubes

27 Unit cubes

## What is a unit cube?

A unit cube is nothing but a cube all of whose sides are 1 unit long as shown below.
This is a unit cube

1. We say its dimension is 1 X 1 X 1.
2. The volume of a 3-dimensional unit cube is 1 cubic unit.
3. By joining unit cubes we can form cubes and cuboids of varied dimension.