Answer : 16 feet
the area of a circle is 201.0624 square feet
The formula for area of the circle is

Where r is the radius and value of π = 3.1416
Given area = 201.0624
Plug the values and find out radius 'r'
area of the circle =

201.0624 =

Divide by 3.1416 from both sides

Take square root on both sides
r = 8
radius = 8 feet
Diameter = radius * 2= 8*2 = 16 feet
the diameter of the circle = 16 feet