## Surface Area of a Cube Lesson

### Cube Surface Area Formula

The formula for surface area of a cube is given as:

**SA = 6a ^{2}**

Where *SA* is the surface area, and *a* is the edge length.

A cube has 6 faces that are all squares. The surface area formula is 6 times the area of a square (area of a square = a^{2}).

INTRODUCING

### Surface Area of a Cube Example Problems

Let's go through a couple of example problems together to practice finding the surface area of a cube.

#### Example Problem 1

Find the surface area of a cube with an edge length of 8.

Solution:

- Let's plug the edge length into the formula.
- SA = 6a
^{2} - SA = 6(8
^{2}) = 384 **The surface area of the cube is 384.**

#### Example Problem 2

What is the edge length of a cube with a surface area of 864?

Solution:

- Let's plug the surface area into the surface area formula and then solve for the edge length
*a*. - SA = 6a
^{2} - 864 = 6a
^{2} - 144 = a
^{2} - a = √144
- a = 12
**The edge length is 12.**