Question #N150

A circle has a diameter of 10. What is the circumference of the circle?
A. 5\pi
B. 10\pi
C. 20\pi
D. 100\pi

Correct Answer is: B

The circumference of a circle is given by the formula C = 2\pi r, where r is the radius of the circle. Since the diameter is 10, the radius is 5. Substituting 5 for r in the formula gives us C = 2\pi (5) = 10\pi.