数学课本中有不少定理、公式的内涵十分丰富，只要我们在学习时认真思考它们的证明过程，就可从中吸取丰富的思想养料，学到一些重要的解题方法．下面以等比性质的证明方法（义务教育初中《几何》第二册第202页）为例，谈谈它给我们的启示．审视等比性质的证明过程：先设题设条 There are quite a lot of theorems and formulas in mathematics textbooks. The meanings are very rich. As long as we seriously consider the process of proofing during our study, we can draw a wealth of ideological nourishment and learn important methods for solving problems. The following uses the method of proof of equal proportions (compulsory education junior high school “Geometry” second volume, page 202) as an example, talk about the enlightenment it gives us. Examining the proof process of equal ratios: first setting the question