area.cpp

此程序求圆的周长和面积

#include<iostream.h>
class Circle
{double radius;
public:
	void Set_Radius(double r)
	{radius=r;}
	double Get_Radius() {return radius;}
	double Get_Girth() {return 2*3.14*radius;}
	double Get_Area() {return 3.14*radius*radius;}
};
void main()
{Circle A,B;
A.Set_Radius(6.23);
cout<<"A.Radius="<<A.Get_Radius()<<endl;
cout<<"A.Girth="<<A.Get_Girth()<<endl;
cout<<"A.Area="<<A.Get_Area()<<endl;
}