A property of close broken line inscribed in a circle - also solution to challenge 这道课本例题的解法对吗
Abstract : this paper gives a formula of directed area for pedal polygon of polygons inscribed in a circle . using this formula , we obtain some fixed value theorems for this kind of pedal polygins . thus some results of pedal triangles are generalized 文摘:给出圆内接多边形的垂足多边形的有向面积公式,并利用该公式获得圆内接多边形的垂足多边形和正多边形的垂足多边形的若干结果,从而推广了垂足三角形的一些结论。