近几年各地中考数学试卷中陆续出现了一些形式新颖的题目 .只要我们稍加注意 ,便不难发现 ,这些题中有相当一部分是来自课本上的“读一读”或“想一想” .例 1　现有四块直角边为ａ、ｂ ,斜边为ｃ的直角三角形纸板 .请从中取出若干块拼图 ,证明勾股定理 .( 1 999,安徽省中考题 In recent years, there have been some new and innovative topics in the mathematics examination papers in various localities. As long as we pay a little attention, it is not difficult to find that a considerable part of these questions are from the textbook “reading” or “think”. Example 1 There are four right-angled triangular cardboards with right-angled sides a and b and oblique-edges of c. Please remove a few pieces of puzzles from them to prove the Pythagorean theorem. (1 999, Anhui Provincial Examination Questions