-- find circumfrance #1:
print('What is the circumfrance of a circle whos radius 5ft^2?')
print('')
pi = math.pi 
radius = 5
r = radius
diameter = (r * 2)
d = diameter
circumfrance = (d * pi)
c = circumfrance
unit = ('ft^2')
-- step by step solution
print('d', '=', '2', 'x', 'r')
print('d', '=','2', '(', r, ')')
print('-----------------------------------------')
print('', 'd', '=', d)
print('')
print('Next :')
print('')
print('c', '=', 'pi', '*', 'd')
print('c', '=', '3.14','(', d, ')')
print('-----------------------------------------')
print('', 'c', '=', c)
print('')
print('Circumfrance', '=', c, unit)