# Thread: Finding the lateral edge of a cube

1. ## Finding the lateral edge of a cube

The surface area of a cube is 864 square inches . Find the lateral edge of the cube.

Thank you muchly ^_^

2. Hello,

A cube is made of 6 identical faces, with an edge of a. So each face will be a² square inches.

So the area of the cube will be 6*a².

Solve for a :

864=6a²

-> a²=144

-> a=...

3. Lol, thank you so much for taking your time to help me! This definately makes more sense now.

a = 12 ^_^