GRE考试

【单选题】If
A、is 25 kilometers east ofB, which is 12 kilo-meters south ofC, which is 9 kilometers west ofD, how far is it, in kilometers, from
A、to
D、


网考网参考答案：A
网考网解析：
Use TACTIC 1 in Chapter 10: draw a diagram. In the figure below, form rectangle BCDE by drawing DE ⊥ AB. Then, BE = 9, AE = 16, and DE = 12. Finally, DA = 20, because right triangle AED is a 3-4-5 triangle in which each side is multiplied by 4. If you don’t realize that, use the Pythagorean theorem to get DA: (DA) 2 = (AE) 2 + (DE) 2 = 256 + 144 = 400 DA = 20. [*] document.getElementById("warp").style.display="none"; document.getElementById("content").style.display="block"; 查看试题解析出处>>