三角形，矩型，圆，多边型的类放到不同的包中，用包的技术组织程序的设计。同时要求程序能从键盘上接受数据以便求解不同的几何图形的周长面积。-Triangle, rectangle, circle, polygon class into a different package, with the package of technical organization design process. Also asked the program to accept data from the keyboar