import math
#
length = float(input('Enter a length, please~'))

if length < 0 :
    print('Length must be >= 0. Please try again.') 
else:
    print('Your input length is', length)
    #The area of a square with side of that length
    area_of_square = length ** 2 
    print('area_of_square:',area_of_square)
    #The volume of a cube with side of that length
    volume = length ** 3 
    print('volume:',volume)
    #The area of a circle with diameter of that length
    radius = length / 2 
    area_of_circle = math.pi * radius **2
    print('area_of_circle:',area_of_circle)
    #The volume of a sphere with diameter of that length
    volume_of_sphere = math.pi * radius ** 3 
    print('volume_of_sphere:',volume_of_sphere)
    #The volume of a cylinder with diameter of that length and side of that length
    volume_of_cylinder = length * math.pi * radius ** 2 
    print('volume_of_cylinder:',volume_of_cylinder)
