Math problem of the day

A circle whose circumference is 12π is inscribed in a square. What is the perimeter of the square?

Answers variants: A. 48π   B. 48   C. 36π   D. 36   E. 24π

Correct answer: B. 48

The circumference is given by the formula C = d*π, where d is the diameter of the circle. In this case d is also the side length of the square. So, P = 4*d = 4*(C/π) = 4*12*π/π = 48.
The answer correct is (B): 48