title: How to figure out if two CGRect intersect?
body: <p>In -drawRect: I want to check if the provided rect intersects with anotherRect.</p>
  
  <p>I'm not good at this geometry math stuff and especially at english so what I want to say is:</p>
  
  <p>If you have two sheets of paper on the desk, and one of them covers the other either completely or just a small portion, it is rectsIntersect = YES.</p>
  
  <p>How to check that out for <code>rect</code> and <code>anotherRect</code>?</p>