Question

Use the correct formula to find the area of a circle if the diameter is 21 mi. Round to the nearest hundredths place. Use 3.14 for π
.(1 point)
Responses

346.19 mi.2
346.19 mi squared

1,384.74 mi.2
1,384.74 mi squared

131.88 mi.2
131.88 mi squared

65.94 mi.2
65.94 mi squared

Answer 1

To find the area of a circle, you can use the formula:

\[
A = \pi r^2
\]

where \(A\) is the area, \(\pi\) is a constant (approximately 3.14), and \(r\) is the radius of the circle.

First, we need to find the radius. The radius is half of the diameter. Given that the diameter is 21 mi:

\[
r = \frac{21}{2} = 10.5 \text{ mi}
\]

Now, we can use the radius to find the area:

\[
A = \pi r^2 = 3.14 \times (10.5)^2
\]

Calculating \( (10.5)^2 \):

\[
(10.5)^2 = 110.25
\]

Now substituting back into the area formula:

\[
A = 3.14 \times 110.25 \approx 346.19 \text{ mi}^2
\]

Thus, the area of the circle is approximately **346.19 mi²**.

So the correct response is:

**346.19 mi squared.**