“两圆外切”是两圆的一种重要的位置关系.特别是动圆在保持与定圆外切的前提下绕定圆滚动一周,动圆的圆心运行的路程有明显的规律,十分耐人寻味.如果由此联想到圆与多边形外切,就会得到一个与此类似的有趣结论,同时也可复习到很多重要的的数学知识.下面我们来一起分享. “Two rounds of outer cut” is an important positional relationship between the two circles. In particular, if the moving circle is maintained on the premise of maintaining the outer circle with the fixed circle, it will roll around the circle for one circle. The distance of the center of circle of the moving circle has obvious rules. , very interesting. If you think of the circle and the polygon outer cut, you will get an interesting conclusion similar to this, but also can review a lot of important mathematical knowledge. Let’s share together.