You can find the surface area of a cube by finding the area of one of the faces and multiplying by 6, with 6 being the number of faces a cube has.
Faces of cubes are squares. To find their area, multiply the edge length by itself.
This all can be represented in the equation 6x^2, with x being the length of one of the sides.
6x^2
x = 9
6(9)^2
First, do 9^2.
9^2 = 81
Then, multiply 6 by 81.
6 • 81 = 486
The surface area of this cube is 486 mm^2.
We use mm^2 because the units are mm (millimeters) and surface area is square, not cubic.
Hope this helps!
