What is the circumference of 16 feet circle?

Assuming circle refers to area you probably wanted to say 16 square feet circle. Area (A); Radius (r); Circumference (C); pi = 3.141593 A = 16 = pi r2 = 3.141593 x r2 => r = 2.256758 C = 2 pi r = 2 x 3.141593 x 2.256758 = 14.179632 Assuming 16 is the radius: C = 2 x 16 x pi = 100. 530976 Assuming 16 is the diameter, its half of the above, 50.266