AreaMain

import java.util.Scanner;

public class AreaMain{
    public static void main(String Args[])
    {
        Area ar1 = new Area();
        Area ar2 = new Area(4,2);
        Area ar3 = new Area(9,7);
        System.out.print("\na = "+ar1.a+" b = "+ar1.b+"Rect area = " + ar1.Rect());
        System.out.print("\na = "+ar2.a+" b = "+ar2.b+"Parallelogram area = " + ar2.Parall());
        System.out.println("\na = "+ar3.a+" b = "+ar3.b+"Triangle area = " + ar3.Tri());
    }
}

class Area {
    int a;
    int b;

    Area()
    {
        System.out.print("\tDefault Const called!\n");
        a = 2;
        b = 3;
    }
    Area(int a, int b)
    {
        System.out.print("\tParameterized Const called!\n");
        this.a=a;
        this.b=b;
    }

    int Rect()
    {
        return a*b;
    }

    int Parall()
    {
        return a*b;
    }

    double Tri()
    {
        return 0.5*(double)(a*b);
    }

}