Write A C++ Program For Class Rectangle.

#include<iostream.h> 
 #include<conio.h> 
 class rec 
 { 
       private: 
                    int I,b; 
       public: 
                    rec() 
                  { 
                           I=b=2; 
                           cout<<"Constructor with Zero Parameter\n"; 
                   } 
                   rec(int a) 
                  { 
                            I=b=a; 
                            cout<<"Constructor with One Parameter\n"; 
                   } 
                   rec(int a,int c) 
                  { 
                             I=a; 
                             b=c; 
                             cout<<"Constructor with Two Parameter\n"; 
                   } 
                   int area() 
                  { 
                             return (I*b); 
                   } 
 }; 
          void main() 
       { 
              clrscr(); 
              rec obj1; 
              cout<<"Area is of First Rectangle: "<<obj1.area() <<endl; 
              rec obj2(3); 
              cout<<"Area is of Square: "<<obj2.area()<<endl; 
              rec obj3(7,7); 
              cout<<"Area is of Third Rectangle: "<<obj3.area()<<endl; 
              getch(); 
        }