I believe there's a mistake in the question, as "r" usually stands for "radius" and not the value of pi. Assuming you meant to ask for the circumference, the correct formula would be:
Circumference = 2πr
where r is the radius of the circle and π (pi) is a mathematical constant approximately equal to 3.14.
Using this formula and the given radius of 6.1 kilometers, we get:
Circumference = 2 x 3.14 x 6.1
Circumference = 38.284 kilometers (rounded to the nearest hundredth)
Therefore, the circumference of the circle with a radius of 6.1 kilometers is approximately 38.28 kilometers.