For this case what you must do is find the diagonal of the square to find the diameter of the circle and then be able to obtain the radius.
We have then:
A = L ^ 2 = 128
L = root (128)
L = 11.3137085
Then, the diagonal of the square knowing its sides is:
d = root ((L) ^ 2 + (L) ^ 2)
d = root ((11.3137085) ^ 2 + (11.3137085) ^ 2)
d = 16 feet
Finally the radius of the circle is:
r = d / 2
r = (16) / 2
r = 8feet
answer:
the radius of the circle is
r = 8feet
