Question

the radius of a circle is 18 kilometres. what is the circles area? round your answer to the nearest hundredth. square kilometres

Explanation:

Step1: Recall the formula for the area of a circle

The formula for the area \( A \) of a circle with radius \( r \) is \( A=\pi r^{2} \).

Step2: Substitute the given radius into the formula

Given that the radius \( r = 18 \) kilometres. Substitute \( r = 18 \) into the formula: \( A=\pi\times(18)^{2} \). First, calculate \( 18^{2}=18\times18 = 324 \). So, \( A=\pi\times324=324\pi \).

Step3: Calculate the numerical value

Using the approximation \( \pi\approx3.14159265 \), we have \( A = 324\times3.14159265\approx1017.876019 \).

Step4: Round to the nearest hundredth

Rounding \( 1017.876019 \) to the nearest hundredth (two decimal places), we look at the third decimal place which is \( 6 \). Since \( 6>5 \), we round up the second decimal place. So, \( 1017.88 \).

Answer:

\( 1017.88 \)