在几何教学中,有时对一个几何命题进行适当的改编,不但会激发起各个层次学生的思维能力,而且会引起各个层次学生极大的兴趣,下面一道几何题的改编就充分说明了这一点。例:△ABC中,AD⊥BC,CE⊥AB,AD、CE相交于O,连结DE,则图中共有多少对相似三角形,请把所有的相似三角形写出并进行证明。本题原题目是求证:△EDO∽△AOE,如果直接证明此结论,对于部分同学来说比较困难,一下子难以找到解题方法,而把题目 In geometry teaching, sometimes the proper adaptation of a geometric proposition not only inspires students’ thinking ability at all levels, but also arouses great interest of students at all levels. This is fully illustrated by the following reorganization of geometric questions. For example: △ ABC, AD ⊥ BC, CE ⊥ AB, AD, CE intersect at O, the link DE, the figure is how many pairs of similar triangles, all the similar triangles to write and prove. The title of the original question is to prove: △ EDO∽ △ AOE, if the direct proof of this conclusion, for some students is more difficult to find a solution to problems at once, and the title