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

79 square mm
79 square mm

15.7 square mm
15.7 square mm

314 square mm
314 square mm

78.5 square mm

Answer 1

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

\[ A = \pi r^2 \]

where \( A \) is the area and \( r \) is the radius of the circle.

Given that the diameter of the circle is 10 millimeters, the radius would be half of the diameter:

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

Now, using \( \pi \approx 3.14 \):

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

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

So, the correct response is:

**78.5 square mm**.