需要帮助使用类获取矩形和圆形的面积

它们需要是类，getArea 需要成为形状的一部分，方法 getArea 需要形状和面积需要受到保护和形状，高度和半径是它们各自子类的一部分 (C++(

#include <iostream>
#include <fstream>
#include <string>
#include <cstdlib>
#include <math.h>
using namespace std;
class shape {
protected:
double area;
public:
double getArea(){return area;};
};
class rectangle:shape {
private:
double width;
double height;
public:
rectangle(){
width=3;
height=4;
}
double getHeight(){return height;};
double getWidth(){return width;};
void setHeight(double h){height=h;};
void setWidth(double w){width=w;};
void setArea(double width, double height){area=height*width;};
};
class circle:shape {
private:
double radius;
public:
circle(){
radius=1;
}
double getRadius(){return radius;};
void setRadius(double r){radius=r;};
void setArea(double width, double height){area=M_PI*(pow(radius,2));};
};
int main () {
rectangle miRectangulo;
circle miCirculo;
cout<<"Area of the rectangle is "<<miRectangulo.getArea()<<endl;
cout<<"Area of the circle is "<<miCirculo.getArea();
return 0;
}

他们确实需要遵循这些特定条件，现在我收到错误"double：：shape getArea(( 无法访问"