Estimate Values of Expressions with Pi Practice

Question

Complete this assessment to review what you've learned. It will not count toward your grade.
4 of 54 of 5 Items
Question
What is the area of a circle with a radius of 2.1 miles? Estimate the area to the hundredths place using 3.14 for π
.

Answer 1

To find the area \( A \) of a circle, you can use the formula:

\[ A = \pi r^2 \]

where \( r \) is the radius of the circle. In this case, the radius is 2.1 miles. Using \( \pi \approx 3.14 \), we can calculate the area as follows:

\[ A = 3.14 \times (2.1)^2 \]

First, calculate \( (2.1)^2 \):

\[ (2.1)^2 = 4.41 \]

Now plug this back into the area formula:

\[ A = 3.14 \times 4.41 \]

Now calculate \( 3.14 \times 4.41 \):

\[ 3.14 \times 4.41 \approx 13.8384 \]

Rounding this to the hundredths place, the estimated area of the circle is:

\[ A \approx 13.84 \text{ square miles} \]