定义了Circle圆形类，在此基础上派生出Cylinder圆柱体类。 Circle圆形类定义以下: class Circle { public: Circle(double r):radius(r

#include <iostream>
#include <iomanip>
using namespace std;

#define PI 3.14

class Circle
{
public:
	Circle(double r):radius(r){ }
	double area(){return PI*radius*radius;} //圆面积
protected:
	double radius; //圆半径 
};

//将程序须要的其余成份写在下面，只提交begin到end部分的代码
//******************** begin ********************

class Cylinder:public Circle
{
public:
	Cylinder(double r,double h):Circle(r),hight(h){ }
	double area(){return PI*radius*radius*2+PI*2*radius*hight;} //圆面积
	double volume(){return PI*radius*radius*hight; }
protected:
	double hight; //圆半径 

};


//********************* end ********************

int main()
{
double r,h;

cout<<setiosflags(ios::fixed);
cout<<setprecision(2);

cin>>r;
Circle c(r);
cout<<c.area()<<endl;

cin>>r>>h;
Cylinder cy(r,h);
cout<<cy.area()<<" "<<cy.volume()<<endl;

return 0; 
}