Answer:
Circumference of circle is 36π feet.
Step-by-step explanation:
Given : area of circle is 324π feet²
We have to find the circumference of the given circle.
Consider Area of circle is 324π feet²
We know, Area of circle = 
Thus, 
Simplify for r , we have,

Taking square root both side, we have,

Circumference of circle is given by 
Substitute, we get,


Thus, Circumference of circle is 36π feet.