input: 
  def compute_rectangle_area(length: float, width: float) -> float:
      """ Compute the area of a rectangle given its length and width.
  
      >>> compute_rectangle_area(5.0, 4.0)
      20.0
  
      >>> compute_rectangle_area(3.5, 2.5)
      8.75
      """
  
output:     return length * width