用多种方法解题 ,不仅可以拓宽视野 ,训练思维 ,而更重要的是归纳解法 ,总结规律 ,提高能力。下面以初中几何第二册“相似形”一章中 P2 55页第十八题的四种解法为例 ,总结有关线段成比例的解法及作辅助线的规律。题目 :如图 1 ,BD=CE,求证 :AC· EF=AB· DF。解法一 :过 E作 E Solving problems in multiple ways not only broadens horizons and trains thinking, but more importantly, induces solutions, sums up laws, and improves abilities. In the following, the four solutions to the eighteenth problem on page P2, page 55 in the “similar form” chapter of the second edition of the geometry of junior high school are taken as an example to summarize the laws concerning the proportional solution of the line and the rules for the auxiliary line. Title: Figure 1, BD = CE, Proof: AC · EF = AB · DF. Solution One: Over E for E