liskov substitution principle

shapes-2.rb

shapes = [Square.new, Rectangle.new]

def set_rectangle_width(shapes)
   shapes.each do |shape|
      shape.width = 5
      shape.height = 6
   end
end

shapes.rb

class Rectangle
  attr_accessor :width, :height
end

class Square
  attr_accessor :side

  def height=(height)
     @side = height
  end

  def width=(width)
     @side = width
  end

  def width
    @side
  end

  def height
    @side
  end
end