Question

(a circle with a line straight through it that says 10)
Given that the measurement is in centimeters, find the area of the circle to the nearest tenth. (Use 3.14 for π)
Responses
A 31.4
31.4 cm 2
B 62.8
62.8 cm 2
C 78.5
78.5 cm 2
D 314.0

Answer 1

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

\[
\text{Area} = \pi r^2
\]

Where \( r \) is the radius of the circle. Given that the line through the circle measures 10 cm, this indicates the diameter of the circle.

To find the radius, you can divide the diameter by 2:

\[
r = \frac{10 \, \text{cm}}{2} = 5 \, \text{cm}
\]

Now, substitute the radius into the area formula. Using \( \pi \approx 3.14 \):

\[
\text{Area} = 3.14 \times (5 \, \text{cm})^2
\]

\[
\text{Area} = 3.14 \times 25 \, \text{cm}^2
\]

\[
\text{Area} = 78.5 \, \text{cm}^2
\]

So, to the nearest tenth, the area of the circle is **78.5 cm²**.

The correct response is **C: 78.5 cm²**.