题目

How the World Wide Web StartedTim Berners-Lee is the man who wrote the software(软件) programme that led to the foundation of the World Wide Web. Britain played an important part in developing the first generation of computers. The parents of Tim Berners-Lee both worked on one of the earliest commercial (商业的) computers and talked about their work at home. As a child he would build models of computers from packing material. After graduating from Oxford University he went on to the real thing. In the 1980s scientists were already communicating using a primitive version (版本) 如图1，在直角梯形ABCD中，AD∥BC，∠B=∠A=90°，操作示例：我们可以取直角梯形ABCD的非直角腰CD的中点P，过点P作PE∥AB，裁掉△PEC，并将△PEC拼接到△PFD的位置，构成新的图形（如图2）．思考发现：小明在操作后发现，该剪拼方法就是先将△PEC绕点P逆时针旋转180°到△PFD的位置，易知PE与PF在同一条直线上．又因为在梯形ABCD中，AD∥BC，∠C+∠ADP=180°，则∠FDP+∠ADP=180°，所以AD和DF在同一条直线上，那么构成的新图形是一个四边形，进而根据平行四边形的定义，可以得出四边形ABEF是一个平行四边形．实践探究：（1）类比图2的剪拼方法，请你分别就图3和图4的两种情形沿一条直线进行剪切，画出剪拼成一个平行四边形的示意图．联想拓展：小明探究后发现：在一个四边形中，只要有一组对边平行，就可以剪拼成平行四边形．（2）如图5的多边形ABCDE中，AE∥CD，若连接AC，则恰有AC∥ED．请你象上面剪法一样沿一条直线进行剪切，将多边形ABCDE拼成一个平行四边形，请你在图5中画出剪拼的示意图，并简要写明剪拼方法（不需证明）．