Comment obtenir la circonférence à partir du rayon

import math
input=input(f'The radius of the circle is : ')
radius = int(input)
diameter = radius * 2 
area = math.pi * math.pow(radius,2) # radius**2
circumference = math.pi*(radius*2)
print(f'The radius of the circle is {radius:.4f}.')
print(f'The diameter of the circle is {diameter:.4f}.')
print(f'The circumference of the circle is {circumference:.4f}.')
print(f'The area of the circle is {area:.4f}sq.')
Agrius