- //习题12.1中的circle.h文件
- //CIRCLE.H
- #include "point.h"
- class Circle:public Point
- {public:
- Circle(float x=0,float y=0,float r=0);
- void setRadius(float);
- float getRadius() const;
- float area () const;
- friend ostream &operator<<(ostream &,const Circle &);
- protected:
- float radius;
- };