Hi!
circumference of a circle = [tex]2\pi r[/tex].
[tex]2\pi 18[/tex]
[tex]36\pi[/tex] [tex]inches[/tex]
(if you use 3.14 as pi, then it would be 113.04 inches)
For more information, see:
https://brainly.com/question/15747260 (extremely good answer!)
https://brainly.com/question/12259848
