The formula to find the circumference of a circle is C = πd, where C is the circumference and d is the diameter. Plugging in the value of the diameter, we have C = π(12) = 12π ft. Using PI ≈ 3.14, the circumference is approximately 37.7 ft. Rounded to the nearest tenth, the circumference is 37.7 ft. Answer: \boxed{37.7}.
