class Rectangle
  attr_accessor :height, :width

  def calculate_area
    width * height
  end
end

class Square < Rectangle
  def width=(width)
    super(width)
    @height = width
  end

  def height=(height)
    super(height)
    @width = height
  end
end

rectangle = Rectangle.new
rectangle.height = 10
rectangle.width = 5
rectangle.calculate_area # => 50

square = Square.new
square.height = 10
square.width = 5
square.calculate_area # => 25