標題範例:Mathematics > Standard Multiple Choice
Read the following SAT test question and then click on a button to select your answer.
A right circular cylinder has height 6 and volume 54π. What is the circumference of its base?
(A) 2π
(B) 3π
(C) 6π
(D) 9π
(E) 18π
謎底:C
【剖析】The volume of a cylinder with radius r and height h is equal to πr²h. Therefore,πr²(6)=54π and r²=9 , so the radius of the cylinder is 3. The circumference of a circle with radius r is equal to 2πr; therefore, the circumference of the base is equal to 6π.