【C++】用类的方法求圆柱等表面积和体积

#include <cstdio>
#include <iostream>
#include <cstdlib>
class Circle//圆
{
	public:
	double r;
	public:
	void print()
	{
		cout<<"r="<<r<<endl;//输出半径
	}
	Circle(double x)//圆的构造函数
	{
		r=x;
	}
	double GetR()//获取圆的半径
	{
		return r;
	}
};
class Sphere:public Circle//球类
{
	public:
	Sphere(double x):Circle(x)//球的构造函数
	{
	}
	double GetTheSphereArea()//获取球的表面积
	{
		double R=GetR();
		return (4*3.14*R*R);
	}
	double GetTheSphereVolume()//获取球的体积
	{
		double R=GetR();
		return ((3.14*R*R*R)*3/4);
	}
};
class Cylinder:public Circle//圆柱类
{
	public:
	double h;
	Cylinder(double x ,double y):Circle(x)//圆柱类的构造函数
{
	h=y;
}
	double GetTheCylinderArea()//获圆柱类的表面积
	{
		double R=GetR();
		return (2*3.14*R*R+2*3.14*R*h);
	}
	double GetTheCylinderVolume()//获圆柱类的体积
	{
		double R=GetR();
		return (3.14*R*R*h);
	}
};
void main()
{
	Sphere Sphere1(2.5);
	double a=Sphere1.GetTheSphereArea();
	cout<<"表面积："<<a<<endl;
	a=Sphere1.GetTheSphereVolume();
	cout<<"体积："<<a<<endl;
}