/*做一个抽象的shape类 有一个可计算面积的抽象方法

1.做矩形和圆形两个类继承shape类 各自计算面积

2.根据两种图形的面积求法各自设置成员变量

3.设置图形类 包含图形名字和一个shape类型的成员 变量 并含一个方法 实现shape类成员的面积操作

4.做一测试类 分别根据不同的shape类对象实现多态*/-/* Do an abstract shape class has a way to calculate the size of an abstract. Do two types of rectangular and circular shape inheritance calculated area of each category 2. In accordance with the size of the two graphics method members separate variables 3. Set graphics category contains the name and a graphic shape types of member variables and methods to achieve a shape with a member of the area of operation of Class 4. to do a test-class shape, respectively, according to different types of multi-modal object* /