Question

Write a formula for the surface area of the cube.

Short answer

The surface area of the cube $=6l^2$.

Step-by-step solution

Step 1. Given information.

The surface area of a 3-dimensional object is the sum of the areas of the faces.

The length of the side of the cube is l.

Step 2. Determine the formula.

The number of sides of the cube = 6.

Then,

The Surface area of a cube is equal to 6 times the surface area per face.

Since the shape of the face of the cube is a square. So, the surface area of the face is equal to the area of the square.

Therefore, the surface area of the face is $l^2$.

This implies that the surface area of the cube is $6\times l^2$.

Step 3. Conclusion.

The surface area of the cube $=6l^2$, where l is the side length of the cube.