text: def cylinder_volume(height, radius=3):
      pi = 3.14159
      return height * pi * radius ** 2
  
  
  # Using the default value.
  print(cylinder_volume(10))
  # 282.7431
  
  
  # Overriding the default value.
  print(cylinder_volume(10, 3))
  # 282.7431
  
  print(cylinder_volume(10, 5))
  # 785.3975
  