A circle has a cirumference that measures 18(pi) inchies. What is the raduis in inches of the circle?

C = 2(pi)r

a) 6
b) 9
c) 18
d) 36

My answer - 9
reason - haft of 18 is 9

is my answer is correct?

3 answers

I change my answer:

C = 2(Pi)r

c = 2 x 18

c = 36

am i correct

btw - i don't remember how to do this because in my math class we didn't get to that yet (learning all the formulas)
so 2πr = 18π
divide by 2π
2πr/(2π) = 18π/(2π)
r = 9

b) is the correct choice.
so i was right the first time

thanks :)