We are asked to explain how the volume of a three-dimensional figure differs from its surface area. Before we do that, let's remember what they are.
Volume
Volume of a solid is the amount of space available in an object. The volume is measured using cubic units, such as cubic meters, m^3. The applet below illustrates the volume of some solids being filled by moving the slider.
In real life we are interested to know the volumes of objects. For example, the volume of a fridge will tell us how much produce we can store in it.
Surface Area
Surface area, on the other hand, is the total area of the surfaces of a solid. The area is measured using square units. Consider how in.^2 means square inches. A net of a solid can be helpful to visualize the surfaces of a three-dimensional figure.
We use surface areas of object in real life too. When we are painting an object, we want to know its surface area so that we can buy the right amount of paint.
Comparison
We can calculate the surface area and volume for any three-dimensional geometrical shape. The main difference is that one is a two-dimensional measure, and the other is a three-dimensional measure. As a result, they have different units.
