package com.java;

class Animalfamily{

public void sound(){

System.out.println("animal makes sound");

}

}

class bird extends Animalfamily{

public void sound() {

System.out.println("bird sound");

}

}

class cat_ extends Animalfamily{

public void sound() {

System.out.println("cat sound");

}

}

class shapes{

public double area(){

return 0;

}

}

class circle_shape extends shapes{

private int radius;

public circle_shape(int radius){

this.radius=radius;

}

public double area(){

return Math.PI*radius*radius;

}

}

class rectangle extends shapes{

private double len;

private double width;

public rectangle(double length,double width){

this.len=length;

this.width=width;

}

public double area(){

return len*width;

}

}

public class Polymorphism {

public static void main(String[] arg){

Animalfamily af = new Animalfamily();

af.sound();

bird b = new bird();

b.sound();

cat_ c = new cat_();

c.sound();

shapes s = new circle_shape(5);

System.out.println("area of circle :"+ s.area());

shapes s1 = new rectangle(2,2);

System.out.println("area of rectangle :"+ s1.area());

}

}