title: ThinkPython - Ex 4.5 - Write a program that draws an Archimedes spiral (or one of the other kinds)
body: <p>Is it just me or everyone who is facing so many problems in attempting this question from exercise of Think Python. 
  I am trying to solve exercises of Chapter 4 but facing so many problem. 
  Exercise 4.5 says Write a program that draws an Archimedes spiral.
  I have this code but its not working in Python.
  I need an easy possible solution for this.
  Kindly help.</p>
  
  <pre><code>from TurtleWorld import *
  
  world = TurtleWorld()
  bob = Turtle()
  
  def polygon(t, length, n):
      t = Turtle()
      for i in range(n):
          fd(t, length)
          lt(t, 300 / n)
  
  polygon(bob, 5, 8)
  </code></pre>