using System;

public class Program

{

    public static void Main()

    {

        Square s= new Square(20);

        Log(s);

        var r = s.Squish(10);

        Log(s);     

        Log(r);

    }

    public static void Log(object o)

    {

        Console.WriteLine(o);

    }

}

​

public class Rectangle

{

    public uint Width { get; private set;}

    public uint Height { get; private set;}

    public Rectangle(uint width, uint height)

    {

        this.Width = width;

        this.Height = height;

    }

    public Rectangle Squish(uint amount)

    {

        // no longer mutates state, thus it's probably safe for inheritance.

        return new Rectangle(this.Width * amount, this.Height / amount);

    }

    public override string ToString()

    {

        return string.Format("Height: {0}, Width: {1}", this.Height, this.Width);

    }

}

​

public class Square : Rectangle

{

    public Square(uint sideLength) : base(sideLength, sideLength)

    {

    }

}