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根据现行普通中学数学教学大纲(修订草案,1956年版)的规定,平面几何在学习了“多边形面积”以后,紧接着就学习“正多边形”。这里提出个人对这一章教学的一些初步看法,供教学中的参考。§1.正多边形在几何教学中的地位和作用我们不妨先从生产实际中常见到的一些问题来谈起: 在金工车间里,钳工根据图样要做一个底面边长为4公厘的正五棱柱的工件,他需选取圆径是多少的材料才是恰当的? 根据立体几何图形的概念,正五棱柱的工件的底面是一个正五边形,显然这就是在已知圆内作一个内接正五边形的问题。如果钳工知道了正多边形的边长和它外接圆直径的相互换算关系,那末就可以通过计
According to the provisions of the current general high school mathematics syllabus (revised draft, 1956 edition), plane geometry learns “polygonal area” and immediately follows “positive polygons”. Here are some of the individual’s preliminary views on this chapter of teaching for reference in teaching. § 1. The status and role of regular polygons in geometry teaching Let us start with some of the common problems in production. In the metalworking workshop, the fitter will use the pattern to make a positive five-by-five mm edge. Prism workpiece, he needs to select the diameter of the material is appropriate? According to the concept of three-dimensional geometry, the bottom of the workpiece is a positive pentagonal prism, this is obviously within the known circle Correct the question of the pentagon. If the fitter knows the mutual conversion between the length of the side of a regular polygon and the diameter of its circumcircle, it can be calculated by