title: calculate 2 points on an outer circle based on 2 points on an inner circle where the 2 sets of points are horizontal
body: <p>Observing the diagram through the link below, where the 2 circles have the same center point:</p>
  
  <p><a href="http://www.graphicsgen.com/CircleQuestion.png" rel="nofollow">http://www.graphicsgen.com/CircleQuestion.png</a></p>
  
  <p>given the center point (X1,Y1), any radius S, and degrees D and E, it is easy to calculate Points (X2,Y2) and (X3,Y3), as follows:</p>
  
  <pre><code>var X2 = X1 + S * (Math.cos(D * (Math.PI / 180)));
  var Y2 = Y1 + S * (Math.sin(D * (Math.PI / 180)));
  var X3 = X1 + S * (Math.cos(E * (Math.PI / 180)));
  var Y3 = Y1 + S * (Math.sin(E * (Math.PI / 180)));
  </code></pre>
  
  <p>So given that lines (X2,Y2),(X4,Y4) and (X3,Y3),(X5,Y5) are horizontal and both perpendicular to (X2,Y2),(X3,Y3), how do you calculate points (X4,Y4) and (X5,Y5) given any radius R?</p>
  
  <p>Thanks</p>