#include <iostream>
using namespace std;
class CCircle{
    
    public :
		void setR(double pr){	
			cin>>r;
	};
    void getPerimeter(){
        double s=0;
        s=6.28*r;
        cout<<"the perimeter is "<<s<<endl;
    };
    void getArea(){
        double m=0;
        m=3.14*r*r;
        cout<<"the area is "<<m<<endl;
    };
    
    private :
    double r;
    
};
////此处编写主函数
int main()
{
CCircle circle;
double pr=0;
cout << "please enter a radius:";
circle.setR(pr);
circle.getArea();
circle.getPerimeter();
    
return 0;
}