人教版初中《几何》第二册第89页例3:图1如图1,要在河边修建一个水泵站,分别向张村、李庄送水,修在河边什么地方,可使所用的水管最短?问题提出要“分别向张村、李庄送水”,所以课本中使用轴对称方法,把河岸看作直线l,找出点A关于l的对称点A′,连结A′B交l于P,连结PA,因为P点到A PEP Junior Geography “Geometry” Volume II Page 89 Example 3: Figure 1 As shown in Figure 1, a water pumping station should be built beside the river to send water to Zhangcun and Lizhuang respectively, where it can be used to repair it. The problem is that the shortest length of water pipe is to “send water to Zhangcun and Lizhuang respectively.” Therefore, in the textbook, the axisymmetric method is used to treat the bank as a straight line l. Find the symmetrical point A′ of point A with respect to l and connect it with A′B. L to P, link PA because P to A