The Basics of Area Examples

Can the area of a pentagon be calculated?

Sure thing! A pentagon is a closed 2D shape. We can find its area faster than a speeding bullet. Though it should really be going the speed limit.

The measurements of a circle are expressed in kilometers. Can we find the area? If so, what units will we use?

A circle is a closed 2D shape, so we can definitely find its area. A shape doesn't need straight edges to have an area. Since its measurements are in kilometers, our unit of area will most likely be square kilometers or km².

A regular dodecagon (12-sided figure) has side lengths of 8 mm. What units will its area be in?

A regular dodecagon is a closed 2D shape, so it will have an area. While we don't have to know how to calculate the exact number just yet, we should know that its area will be expressed in units of mm².

If two polygons are congruent, their areas are congruent. True or false?

This is true! If the size and angles of a shape are identical in every way, the areas they contain will be identical as well. The opposite, on the other hand, is not true. Just because two shapes have the same area does not mean they are congruent.