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《中小学数学》(初中版)2012年7—8期上有一篇文章:《一道课本错题的教学设计》(以下简称“原文”),笔者研读后,认为该习题无论是从问题的命制,还是解答,都没有出错.现将我的想法与同行探讨,不妥之处请斧正.为了便于说明,先将原题摘录如下:两个相似三角形的一对对应边分别为32cm和12cm.(1)已知它们的周长相差45cm,求这两个三角形的周长;(2)已知它们的面积相差550cm~2,求这两个三角形的面积.(上海科学技术出版社出版,义务教育课程标准实验教科书《数学·九年级(上册)》第85页习题4)
“Primary and secondary mathematics” (junior high school version) 2012 7-8 on an article: “a textbook wrong teaching design” (hereinafter referred to as “original”), the author study, that the exercise no matter from the problem Is still no answer, are not wrong. Now my thoughts and colleagues to explore, the wrong place Please correct. For the sake of explanation, first extract the original title as follows: Two similar triangles of a pair of corresponding sides were 32cm And 12cm. (1) Knowing that their perimeters differ by 45cm, find the perimeter of these two triangles. (2) Know that their areas vary by 550cm ~ 2 and find the area of these two triangles. (Shanghai Science and Technology Press. Society, compulsory education curriculum standard experimental textbook “ninth grade mathematics (the first volume)” on page 85 exercise 4)