title: Python Turtle unit of measurement
body: <p>When we instantiate a turtle object, we can draw a circle. I wonder about the radius parameter of the <code>circle()</code> method. </p>
  
  <pre><code>import turtle
  myTurtle = turtle.Turtle()
  myTurtle.circle(50)
  </code></pre>
  
  <p>What is the unit of measurement of this parameter? </p>
  
  <p>Does the radius equal to 50 pixels or 50 inches?</p>