Source Code to Implement Inheritance in C++ Programming
/* C++ Program to calculate the area and perimeter of rectangles using concept of inheritance. */
#include <iostream>
using namespace std;
class Rectangle
{
    protected:
       float length, breadth;
    public:
        Rectangle(): length(0.0), breadth(0.0)
        {
            cout<<"Enter length: ";
            cin>>length;
            cout<<"Enter breadth: ";
            cin>>breadth;
        }
};
/* Area class is derived from base class Rectangle. */
class Area : public Rectangle   
{
    public:
       float calc()
         {
             return length*breadth;
         }
};
/* Perimeter class is derived from base class Rectangle. */
class Perimeter : public Rectangle
{
    public:
       float calc()
         {
             return 2*(length+breadth);
         }
};
int main()
{
     cout<<"Enter data for first rectangle to find area.\n";
     Area a;
     cout<<"Area = "<<a.calc()<<" square meter\n\n";
     cout<<"Enter data for second rectangle to find perimeter.\n";
     Perimeter p;
     cout<<"\nPerimeter = "<<p.calc()<<" meter";
     return 0;
}