title: Testing for intersection between two arcs
body: <p>I have two arcs, defined by objects containing their start and end angles, their centres, and their radii.</p>
  
  <p>The definition looks something like this:</p>
  
  <pre><code>arc = {
      start: 0,
      end: Math.PI,
      radius: 10,
      centre: [0, 0]
  }
  </code></pre>
  
  <p>I want to know if the arcs intersect at any point, but I'm unsure how to do this. I've tried finding points of intersection between the two circles with the same radii and centres of the arcs, and then checking if those points are on both arcs, but this is complicated by the fact that my start/end angles might not be between 0 and 2π - they could be any value, and I'm not sure how to check whether the circle intersections lie on the arcs.</p>
  
  <p>How can I check whether two arcs intersect? (For what it's worth, I'm using JavaScript, but any language would work as an answer)</p>