Gotcha, bro.
(I don't know what pi is, so I'm gonna assume that it is 3.14)
C=pi x diameter
First, multiply the radius by 2 so you have the diameter.
3x2=6
Second, multiply 3.14 (pi) by 6 (diameter)
3.14x6=18.84
Therefore, the circumference is 18.84.
(19 if you round it to the whole number)
Hope this helps!
(btw if pi is something else, use these steps to help you out)
