# Question #7515d

May 24, 2017

$36 \pi$ i${n}^{2}$ or about 113 i${n}^{2}$

#### Explanation:

A dinner plate is a circle. To find the area of a circle, use the equation $A = \pi \cdot {r}^{2}$ where A is Area, $\pi$ is a constant equal to about 3.14 (the constant is irrational; 3.14 is an approximation), and $r$ is the radius of the circle.

In this problem, the diameter is 12 inches. Diameter is twice the length of the radius so to find the radius, divide 12 by 2:

$\frac{12}{2} = 6$
The radius is 6 inches.

Now, we have all the information necessary to commplete the problem. We substitute the values in to the equation to get the equation
$A = \pi \cdot {6}^{2}$
simplified to:
$A = 36 \pi$ i${n}^{2}$ ****

because ${6}^{2}$ is $6 \cdot 6$, which is 36

The answer can be left in terms of $\pi$, or it can be approximated using the value 3.14 (or a longer approximation such as 3.141592).

Therefore:
$A = 36 \cdot 3.14$
$A \approx 113$ i${n}^{2}$ ****

Both answers are correct, but the first one which leaves $\pi$ in the answer is more exact because $\pi$ is an exact number without substituting an inexact approximation.