命令：SS后选着所有有面积的图形后回车，自动计算全部面积。命令LL后选着所有线段后回车，自动计算全部线条长度-Command: SS after the election of all the graphics area after a carriage return, automatic calculation of the total area. LL command after the election of all segments after the carriage return,

用于绘画点线面，简单实用快捷。是初学者的首选。-For drawing points, lines and simple, practical and quick. It is the first choice for beginners.