GRE考试

根据网考网考试中心的统计分析，以下试题在2019/2/18日GRE考试习题练习中，答错率较高，为：77%
【单选题】In the figure at the right, WXYZ is a square whose sides are 12.AB,CD,EF, and GH are each 8, and are the diameters of the four semicircles. What is the area of the shaded region

A、144-128π
B、144-64π
C、144-32π
D、144-16π
E、16π
网考网参考答案：C，答错率：77%
网考网试题解析：
If you don’t know how to solve this, you must use TACTIC 4 and guess after eliminating the absurd choices. Which choices are absurd Certainly, A and B, both of which are negative. Also, since Choice D is about 94, which is much more than half the area of the square, it is much too big. Guess between Choice C (about 43) and Choice E (about 50). If you remember that the way to find shaded areas is to subtract, guess C. **The area of the square is 12 2 = 144. The area of each semicircle is 8π, one-half the area of a circle of radius 4. So together the areas of the semicircles is 32π document.getElementById("warp").style.display="none"; document.getElementById("content").style.display="block"; 查看试题解析出处>>