Question

the radius of a circle is 3 kilometers. what is the circles circumference?
r=3 km
round your answer to the nearest hundredth.
kilometers
submit

Explanation:

Step1: Recall the formula for the circumference of a circle

The formula for the circumference \( C \) of a circle is \( C = 2\pi r \) or \( C=\pi d \) (where \( d \) is the diameter and \( d = 2r \)). Here, we know the radius \( r = 3 \) kilometers, so we can use \( C = 2\pi r \).

Step2: Substitute the value of \( r \) into the formula

Substitute \( r = 3 \) into \( C = 2\pi r \), we get \( C=2\times\pi\times3 \).

Step3: Calculate the value

First, \( 2\times3 = 6 \), so \( C = 6\pi \). Using \( \pi\approx3.14159 \), we have \( C\approx6\times3.14159 = 18.84954 \).

Step4: Round to the nearest hundredth

Rounding \( 18.84954 \) to the nearest hundredth (two decimal places), we look at the third decimal place which is \( 9 \). Since \( 9\gt5 \), we round up the second decimal place. So \( 18.84954\approx18.85 \).

Answer:

\( 18.85 \)