08. Circle Area and Perimeter

from math import pi

radius = float(input())
area = radius ** 2 * pi
perimeter = 2 * pi * radius
print(f'{area:.2f}')
print(f'{perimeter:.2f}')


Или тарикатската:

from math import pi

radius = float(input())

print(f'{pi * radius ** 2:.2f}\n{2 * pi * radius:.2f}')

И тарикатската без math:

r = float(input())
print(f'{r ** 2 * 3.141592653589793:.2f}\n{2 * 3.141592653589793 * r:.2f}')