Question

what is the circumference of this circle? r = 2 km 10.14 km 18.16 km 15.25 km 12.56 km

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 \( r = 2\space km \), so we can use \( C = 2\pi r \).

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

Substitute \( r = 2\space km \) and use \( \pi\approx3.14 \) into \( C = 2\pi r \). So \( C=2\times3.14\times2 \).

Step3: Calculate the result

First, calculate \( 2\times2 = 4 \), then multiply by \( 3.14 \): \( 4\times3.14 = 12.56\space km \).

Answer:

12.56 km