A semicircle has a radius of 11. What is the approximate perimeter of the semicircle? Options.
A) 45	B) 51	C) 57	D) 63	E) 69
The perimeter of a circle is 2*pi*r.   The perimeter of a semicircle is 2*pi*r/2 + 2r = pi*r + 2r   The perimeter is pi*11 + 2*11 which is about 57.   The answer is 57.
<result>C</result>
A semicircle has a radius of 11. What is the approximate perimeter of the semicircle?