exercise_4.py

print(
  '-----------------------------------------\n'\
  'Practical python education || Exercise-4:\n'\
  '-----------------------------------------\n'
  )

print(
  'Task:\n'\
  '-----------------------------------------\n'\
  'Write a Python program which accepts the radius of a circle from the user and compute the area:"\n'
  )

print(
  'Solution:\n'\
  '-----------------------------------------'\
  )

from math import pi
r = float(input("R = "))
print("S = piR^2 = pi" + str(r) + "^2 = " + str(pi * r**2))

print(
  '\n-----------------------------------------\n'\
  'Copyright 2018 Vladimir Pavlov. All Rights Reserved.\n'\
  '-----------------------------------------'
  )