GMAT考试

【单选题】If the area of a circle is 81π, then the diameter of the circle is
A、9
B、18
C、36
D、9π
E、18π

网考网参考答案：B
网考网解析：
The formula for the area of a circle is πr 2 . Therefore, the radius of this circle is the square root of 81, or 9. The diameter is twice the radius, so 18. document.getElementById("warp").style.display="none"; document.getElementById("content").style.display="block"; 查看试题解析出处>>