A cube has 6 sides that are all equal. So the surface area of a cube is. SA = a^2 + a^2 + a^2 +a^2 + a^2 + a^2=6*a^2 . In other words, we add all the areas of the 6 sides. read more
Surface area of a cube To derive the formula of the surface area of a cube, you will need to start with a cube as shown below and call the length of one side a. read more