title: Trilateration in a 2D plane with signal strengths
body: <p>first question to StackOverflow, please be gentle.</p>
  
  <ul>
  <li>I am trying to find the equation (and then the algorithm for) the center point of three different points on a 2D cartesian plane, given a certain magnitude or "signal strength".  These signal strengths are all on a scale relative to each other, but shouldn't necessary be conflated with "radius" of a circle. </li>
  </ul>
  
  <p>Wikipedia entry on trilateration:
  <a href="http://en.wikipedia.org/wiki/Trilateration" rel="nofollow noreferrer">http://en.wikipedia.org/wiki/Trilateration</a></p>
  
  <p>I've also checked out this thread, but it's a little different than what I need
  <a href="https://stackoverflow.com/questions/2813615/trilateration-using-3-latitude-and-longitude-points-and-3-distances">Trilateration using 3 latitude and longitude points, and 3 distances</a></p>
  
  <p>A general equation is nice, but I'll provide some sample data points here for testing:</p>
  
  <p>P1: X,Y = 4153, 4550  // Magnitude or Signal strength = 143<br>
  P2: X,Y = 4357, 4261  // Magnitude or Signal strength = 140<br>
  P3: X,Y = 4223, 4365  // Magnitude or Signal strength = 139  </p>
  
  <p>My general sense is that these points need to be translated to be on the same scale (the signal strengths and the points), but I could be wrong.</p>
  
  <p>Thoughts? TIA</p>