在CAD实现闭合PL线和闭合简单直线的面积直接计算,非常适合才CAD的竣工测量里面实用,通常情况下,CAD只能计算PL线围成的面积,而该程序解决了简单直线的自动闭合判断和面积计算-CAD to achieve closure in the PL line and closed simple direct calculation of the size of a straight line, very suitable for measuring only the completion of CA