# A circle has a diameter of 18 inches. What is its approximate area?

254.47

Explanation

The area of a circle is given by the formula $$A = {\pi}r^2$$ where r is the radius of the circle. The radius of a circle is its diameter divided by two so:
$$r = \frac{d}{2} = \frac{18}{2} = 9$$
By definition, π is approximately 3.14 so:

$$A = {\pi}r^2 = 3.14 \times 9^2 = 3.14 \times 81 = 254.47$$