using System;

​

public class Program

{

    public static void Main()

    {   

        Rectangle rect = new Rectangle(10,20);

        Console.WriteLine("Width = {0}, Length = {1}, Area = {2}", rect.Width, rect.Length, rect.GetArea());

        //rect.Length = 33;

        rect.changePolygonLength(33);

        Console.WriteLine("Width = {0}, Length = {1}, Area = {2}", rect.Width, rect.Length, rect.GetArea());

    }

}

​

internal class Polygon

{

    public double Length{get; protected set;}

    public double Width {get; protected set;}

    public void changePolygonLength(double newLength)

    {

        Length = newLength;

    }

}

​

class Rectangle: Polygon

{

    public Rectangle(double length, double width) 

    {

        Length = length;

        Width = width;

    }

    public double GetArea()

    {

        return Length * Width;

    }

    /*

    public void changeRectangleLength(double newLength)

    {

        Length = newLength;

    }

    '*/

​

}

​