Question

What is the area of a circle with a diameter of 10 millimeters? Estimate the area to the tenths place using 3.14 for π .(1 point)
Responses

15.7 square mm
15.7 square mm

79 square mm
79 square mm

78.5 square mm
78.5 square mm

314 square mm

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. The radius is half of the diameter. Given that the diameter is 10 millimeters, the radius \( r \) is:

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

Now, substitute \( r \) into the area formula using \( \pi \approx 3.14 \):

\[
\text{Area} = 3.14 \times (5)^2
\]
\[
\text{Area} = 3.14 \times 25
\]
\[
\text{Area} = 78.5 \text{ square mm}
\]

So, the area of the circle is approximately **78.5 square mm**.

The correct response is:

**78.5 square mm**