標題範例:Mathematics > Standard Multiple Choice
Read the following SAT test question and then click on a button to select your answer.
The circle shown above has center O and a radius of length 5. If the area of the shaded region is 20π, what is the value of X?
(A) 18
(B) 36
(C) 45
(D) 54
(E) 72
謎底:A
【剖析】