# Question #04486

May 19, 2016

Rounded to nearest foot $\to 314 {\text{ feet}}^{2}$

#### Explanation:

Let the radius be $r$
Let the diameter be $d$
Let area be $a$

Known:
$a = \pi {r}^{2}$

Same equation in a different form

$r = \frac{d}{2} \implies \pi {r}^{2} \to \pi {\left(\frac{d}{2}\right)}^{2} = \pi {d}^{2} / 4$
'~~~~~~~~~~~~~~~~~~~~~~~~~~~

Given that $d = 20 f t$ we have

$a = \pi \frac{{20}^{2}}{4}$

$a = 314.159 {\text{ feet}}^{2}$ to 3 decimal places

Rounded to nearest foot $314 {\text{ feet}}^{2}$