Utilizing the extension of the polygon exteriorangle sum theorem, directions of curvilinear polygons were judged and redundant polygons were deleted.
利用多边形外角定理的推广，判断偏置后曲线多边形的旋向，删除多余多边形。
2
From the Angle of economics the development of country touring has strong characteristics of exterior and communal that belonging to the traditional realm of market failure.
从经济学角度，乡村旅游开发具备强外部性和公共性特征，属于市场失灵的传统领域。
3
A second method is to furnish the surfaces with hinges and to use an exterior sector with drilled holes for each Angle setting.