By definition the area of a circle is given by:
A = pi * r ^ 2
Rewriting:
A = pi * (d / 2) ^ 2
A = (pi / 4) * (d) ^ 2
Where,
d: diameter.
By clearing the diameter we have:
d = ((4 / pi) * A) ^ (1/2)
Substituting the area
d = ((4 / pi) * (16)) ^ (1/2) = 4.51 feet
answer:
The diameter of the rug is 4.51 feet
