output_description: Print the area and circumference of the circle in a line. Put a single space
  between them. The output should not contain an absolute error greater than
  10-5.
input_description: A real number r is given.
attempt: r=float(input())
  print("{0:.6f} {1:.6f}".format(r**2*3.141592653589,r*2*3.141592653589))
  
problem_description: Circle
  
  Write a program which calculates the area and circumference of a circle for
  given radius r.
samples: [{"input": "2", "output": "12.566371 12.566371"}, {"input": "3", "output": "28.274334 18.849556"}]