So, to find the find the amount of fencing required, or the circumference of the gardening, pot...
Area = pi * r^2
125 square feet = pi *r^2
125/ pi = r^2
39.79 = r^2
root square of 39.79 = r
6.31 = r
To find the circumference, the formula is: pi * D (or Pi * r * 2)
therefore,
C = pi * 6.31 *2
C = 39.65 feet
therefore, 39.65 feet of fencing is needed.
hope this helps