A semicircle has a radius of 9. What is the approximate perimeter of the semicircle?	Choose the most appropriate option.
A) 16	B) 25	C) 33	D) 46	E) 58

Rationale: "the perimeter of a circle is 2 * pi * r . the perimeter of a semicircle is 2 * pi * r / 2 + 2 r = pi * r + 2 r the perimeter is pi * 9 + 2 * 9 which is about 46 . the answer is d ."
Answer: D