论文部分内容阅读
笔者在教学苏科版数学七年级下学期第七章《平面图形的认识(二)》时,发现有类似如下的一类试题,它可以归纳为折叠类,也可以把它归纳为寻找等量关系类,有不少学生对此种题型有疑惑,不知该如何下笔,其实静下心来,细细琢磨,也不难发现其中的奥秘,当然,解好数学题还得要寻找到解决这一类问题的思路,现笔者提供如下,与读者朋友共同探讨.试题再现:如图,将ΔABC纸片沿DE折叠,使点A落在四边形BCDE内点A′的位置,探索∠4与∠1+∠2之间的数量关系,并说明理由.
The author in the teaching of the Suke version of mathematics seventh grade next semester seventh chapter “understanding of graphic graphics (b)”, I found similar to the following class of questions, which can be summarized as folded class, you can also find it to find the same amount Relationship class, many students have doubts about this type of questions, I do not know how to write, in fact, calm down, carefully pondering, it is not difficult to find the mystery, of course, solve the mathematical problems have to find to solve this A class of issues of ideas, the author provides the following, together with the reader friends to explore. Reproduction of test questions: As shown, the ΔABC sheet folded along the DE, the point A falls in the quadrilateral BCDE point A ’position to explore ∠ 4 and ∠ 1 + ∠2 the relationship between the number and explain the reasons.