title: Draw part of a circle
body: <p>For an iPhone application I want to draw a circle, that is only for an x percentage filled.</p>
  
  <p>Something like this:</p>
  
  <p><img src="https://i.stack.imgur.com/tiyuY.png" alt="alt text"></p>
  
  <p>I have no problems calculating the radius, the degrees or the radians, that is no problem. Also drawing the circle is already done. But how do I get the iPhone SDK to draw the part that is filled.</p>
  
  <p>I can draw a rectangle that size, but not part of a circle.</p>
  
  <p>I just want to draw that on a a normal context.</p>
  
  <p>Hope someone can give me any pointers here.</p>