Find the exact circumference, in terms of , of a circle with the given radius.
x/2 miles
c = miles

By definition, when we say circumference, this is the measure or the distance around the circle. To find the circumference of a circle we use this formula. C = π x the diameter of the circle or C = 2πr . 
Given that the radius is x/2 miles, let us plug in the values.
So C = 2(3.14)(x/2)
C = 6.28 (x/2)
C= 6.28x/2
C = 3.14x
So the circumference of the given circle above would be 3.14x miles. Hope this answer helps.