Surface Area of Solids

Trying to wrap a present? Using just the right amount of wrapping paper requires a knowledge of solids and surface area. You need to know the shape of box, container, etc. that you are wrapping and the correct surface area formula in order to determine how much paper you need to cover your gift.

 A solid is essentially comprised (made up of) several smaller 2D shapes. When we take the total surface area of a solid we are actually adding up the areas of all the 2D shapes.

 

The cube above is composed of 6 identical squares. The area of each square (on the right) is the same, so total surface area of the cube (on the left) is sum of the areas of all six squares. So if the sides of the square were 2cm, the area of one square is 2 x 2 = 4 sq. cm. The total surface area would then be 6(2 x 2) or 2x2 +2x2 +2x2 +2x2 +2x2 +2x2, which equals 24 sq. cm.

Below is a chart of sample solid shapes: