【摘要】 很多画法几何及机械制图教材中,在几何作图一节中,均出现了对圆周五等分(即作正五边形)求法问题。但只给出其作图方法,而对其为何如此作图,却无回答。文中给出作图法的证明及求解过程,使学生能知其然,更能知其所以然。更多还原

【Abstract】 In the Geometry Drawing section of many descriptive geometry and mechanical drawing books, the drawing method for five even-divided circumference and regular-pentagon were given,but its proof were not given. In this paper,the whole solution were shown, so that students can understand not only how to do it, but also why did so.更多还原