Answer:
[tex]r=9[/tex]
Step-by-step explanation:
The equation to find the circumference of a circle when given the radius is the following,
[tex]C=r(\pi)(r)[/tex]
There (C) represents the circumference, (r) represents the radius, and ([tex]\pi[/tex]) represents the irrational numbers (3.1415...)
Substitute in the given values and backsolve for the radius,
[tex]18(\pi)=2(\pi)(r)[/tex]
Inverse operations,
[tex]18(\pi)=2(\pi)(r)[/tex]
[tex]9=r[/tex]
