9 Abstract Classes

abstract class Figure
 {
   double dim1;
   double dim2;
   Figure(double a, double b)
    {
      dim1 = a;
      dim2 = b;
    }

   abstract double area();
 }

class Rectangle extends Figure
 {
   Rectangle(double a, double b)
    {
      super(a, b);
    }

   double area()
    {
      System.out.println("Inside Area for Rectangle.");
      return dim1 * dim2;
    }
 }

class Triangle extends Figure
 {
   Triangle(double a, double b)
    {
      super(a, b);
    }

   double area()
    {
      System.out.println("Inside Area for Triangle.");
      return dim1 * dim2 / 2;
    }
 }

class AbstractAreas
 {
   public static void main(String args[])
    {

      Rectangle r = new Rectangle(9, 5);
      Triangle t = new Triangle(10, 8);
      Figure figref;
      System.out.println("Area is " + r.area());
      System.out.println("Area is " + t.area());
    }
 }