Abstract Class

Create an abstract class Shape with method display (). Create two class Rectangle and Circle which extend this Shape class and use method display () of it.

import java.io.DataInputStream;
abstract class Shape
{
    abstract void display(int a,int b);
}
class Rectangle extends Shape
{
    int rec;
    void display(int l,int b)
    {
        rec=l*b;
        System.out.println("Ractangle are :===>"+rec);
    }
}
class Circle extends Rectangle
{
    float ans;
    void display(float r)
    {
        ans=3*r*r;
        System.out.println("Circle are:===>"+ans);
    }
}
class AbstractMethod
{
    public static void main(String args[])
    {
        int a,b,c;
        try
        {
            DataInputStream obj=new DataInputStream(System.in);
            Circle cn=new Circle();
            System.out.print("Radius--->");
            a=Integer.parseInt(obj.readLine());
            System.out.print("Lenth---->");
            b=Integer.parseInt(obj.readLine());
            System.out.print("Breadth-->");
            c=Integer.parseInt(obj.readLine());
            cn.display(a);
            Rectangle r=new Rectangle();
            r.display(b,c);
        }
        catch(Exception e)
        {
            System.out.println(e);
        }
    }
}