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圆的无滑动滚动问题,是初中数学中的常见问题,由于解决此类问题需要一定的空间想象能力,许多同学认为较难.通过多年的教学经验,现选取三例有代表性的题目,希望通过分析、讲解,在前两例指出同学们通病的基础上,第三题进一步透彻理解、灵活运用,并拓展联想,找出规律,抓住本质,即:只要计算出滚动圆圆心所经过的路程,此类问题便可迎刃而解.例1(如图)一个等边三角形的边长与它的一边
The problem of round non-slip scrolling is a common problem in maths of junior middle schools, which needs some space imagination to solve such problems, and many students find it more difficult. Through years of teaching experience, three representative topics are now selected, Based on the analysis and explanation, the first two cases indicate that the common problems of the students are based on the third question to further understand and flexibly use, and expand the association to find out the law, to grasp the essence, that is: Distance, such problems can be solved.Example 1 (pictured) side of an equilateral triangle with its side