using System;

​

public class Rectangle

{

    private double length;

    private double width;

    public Rectangle(double l,double w)

    {

        length = l;

        width = w;

    }

    public double GetArea()

    {

        return length * width;

    }

    public static void Main(String[] args)

    {

        Rectangle rect = new Rectangle(10.0, 20.0);

        double area = rect.GetArea();

        Console.WriteLine("area of rectangle is = {0}",area);

        Console.ReadLine(); 

    }

}