What is the diameter of a 3000 sq ft circle?

Remember

A = pi r^2

Hence

3000 = pi r^(2)

r^(2) = 3000 / pi ( =3.14) = 954.92965... sq.ft.

r = sqrt(954.92965... ) = 30.90193616 ft.

Now remember the diamter(d) is twice the radius(r)

d = 2r

Hence d = 2(30.90191616...) = 61.80387232... ft.

d =~= 61.8 ft.