#include <iostream>
using namespace std;
class rectangle
{
    private:
        int width;
        int length;
    public:
        void Setrectangle(int w,int l)
        {  width=w;
           length=l;
        }
        int rectangleArea()
        {  int area;
           area=width*length;
           return (area);
        }
        int rectanglePerimeter();
        
};  


int rectangle::rectanglePerimeter()
{       int p;
        p=2*(width+length);
        return (p);
}

void main()
{       int w;
        int l;
        rectangle r1;
        r1.Setrectangle();
        cout<<"请输入矩形的宽度："<<endl;
        cin>>w;
        cout<<"请输入矩形的长度："<<endl;
        cin>>l;
        cout<<"矩形的面积是："<<r1.rectangleArea()<<endl;
        cout<<"矩形的周长是："<<r1.rectanglePerimeter()<<endl;
}
   
这个程序哪里错了？我只是想要求矩形的面积。什么成员函数的