1// Aim: Program to perform Abstract Class operations (Number of Sides).
2abstract class NumberOfSidesTask {
3    abstract void numberOfSides();
4}
5
6class Rectangle extends NumberOfSidesTask {
7    void numberOfSides() {
8        System.out.println("Rectangle has 4 sides.");
9    }
10}
11
12class Triangle extends NumberOfSidesTask {
13    void numberOfSides() {
14        System.out.println("Triangle has 3 sides.");
15    }
16}
17
18class Hexagon extends NumberOfSidesTask {
19    void numberOfSides() {
20        System.out.println("Hexagon has 6 sides.");
21    }
22}
23
24public class NumberOfSides {
25    public static void main(String[] args) {
26        NumberOfSidesTask rectangle = new Rectangle();
27        NumberOfSidesTask triangle = new Triangle();
28        NumberOfSidesTask hexagon = new Hexagon();
29
30        rectangle.numberOfSides();
31        triangle.numberOfSides();
32        hexagon.numberOfSides();
33    }
34}