Design a simple test application to demonstrate dynamic polymorphism in JAVA

Hi,

here is a program to design classes for point, shape, Rectangle, Square,
Circle, Ellipse, Triangle, Polygon, etc.

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import java.math.*;
class shapes
{
    double dim1;
    double dim2;

    shapes()
    { 
    }
    shapes(double a,double b)
    {
        dim1=a;
        dim2=b;
    }
    double area()
    {
        System.out.println("calculation of area  & perimeter ");
                return 0;
    }
        double peri()
    {
        System.out.println("***********************************");
                return 0;
        }
}
class rect extends shapes
{
    rect(double a,double b)
    {
        super(a,b);
    }
    double area()
    {
        System.out.println("Area of rectangle");
        return dim1*dim2;
    }
    double peri()
    {
        System.out.println("Perimeter of rectangle");
        return 2*(dim1+dim2);
    }
}









class tri extends shapes
{
    double dim3;
    tri(double a,double b,double c)
    {
        super(a,b);
        dim3=c;
    }
    double area()
    {
        System.out.println("Area of triangle");
        return dim1*dim2/2;
    }
    double peri()
    {
        System.out.println("Perimeter of triangle");
        return (dim1+dim2+dim3);
    }
}
class sqa extends shapes
{
    sqa(double a,double b)
    {
        super(a,b);
    }
    double area()
    {
        System.out.println("Area of square");
        return dim1*dim1;
    }
    double peri()
    {
        System.out.println("Perimeter of square");
        return (4*dim1);
    }
}
class circle extends shapes
{

    circle(double a,double b)
    {
        super(a,b);
    }








    double area()
    {
        System.out.println("Area of circle");
        return 3.14*dim1*dim1;
    }
    double peri()
    {
        System.out.println("Perimeter of circle");
        return (2 * 3.14 * dim1);
    }
}
class parlel extends shapes
{
    parlel(double a,double b)
{
        super(a,b);
    }
    double area()
    {
        System.out.println("Area of parllelogram");
        return dim1*dim2;
    }
    double peri()
    {
        System.out.println("Perimeter of parllelogram");
        return 2*(dim1+dim2);
    }
}
class ellip extends shapes
{
    ellip(double a,double b)
    {
        super(a,b);
    }
    double area()
    {
        System.out.println("Area of ellipse");
        return 3.14*dim1*dim2;
    }
    double peri()
    {
        System.out.println("Perimeter of ellipse");
        return 2*3.14*Math.sqrt((dim1*dim1 + dim2*dim2)/2);
        }}







class areaperi
{
    public static void main(String []args)
    { double result;
        //shapes shapref;
                shapes shapref=new shapes();
        rect r=new rect(10,10);
        tri t=new tri(10,8,5);
        sqa s=new sqa(20,30);
        circle c= new circle(35,35);
        parlel p=new parlel(45,35);
        ellip e=new ellip(50,60);
                  shapref.area();
                   shapref.peri();
        shapref = r;
        System.out.println(+shapref.area());
        System.out.println(+shapref.peri());
        shapref = t;
        System.out.println(+shapref.area());
        System.out.println(+shapref.peri());
        shapref = s;
        System.out.println(+shapref.area());
System.out.println(+shapref.peri());
        shapref = c;
        System.out.println(+shapref.area());
        System.out.println(+shapref.peri());
        shapref = p;
        System.out.println(+shapref.area());
        System.out.println(+shapref.peri());
        shapref = e;
        System.out.println(+shapref.area());
        System.out.println(+shapref.peri());
        System.out.println("***************************************");
        }
        }