题目

网格中每个小正方形的边长都是．在下列各个图中画一个格点，使，并且注明相似比．相似比为________； 相似比为________. 答案：【答案】图见解析，相似比为2；图见解析，相似比为：.【解析】根据网格结构，利用三边对应成比例两三角形相似，根据勾股定理作出相似的三角形，并计算相似三角形的相似比即可．如图所示：相似比为：2.如图所示：相似比为：.Tony：Hi, Joy. Would you like to help to save the environment?Joy：  1  What can I do?Tony：Well, first, you can start by turning off the lights.Joy：Yes. That’s easy. Sometimes I turn on the lights without thinking. What’s next?Tony：Second, listen.   2  Don’t take a bus or a taxi if you don’t have to.Joy：That will save money, too.   3 Tony：  4 Joy：Mm, newspapers, magazines, mails … We get a lot of paper at home. Good idea.Tony：And last, take a bag when you go shopping.   5 Joy：OK. My parents do most of the shopping. I’ll tell them.A．You can ride a bike.B．I don’t know.C．Don’t use plastic bags.D．What else?E. Try to recycle paper.