title: Solving circle equations
body: <p>I'm looking for some assistance with solving the below equations in Java</p>
  
  <pre><code>(a-x1)^2 + (b-y1)^2 = r1^2 + r^2
  (a-x2)^2 + (b-y2)^2 = r2^2 + r^2
  (a-x3)^2 + (b-y3)^2 = r3^2 + r^2
  </code></pre>
  
  <p>Values of <code>x1</code>, <code>y1</code>, <code>r1</code>, <code>x2</code>, <code>y2</code>, <code>r2</code> &amp; <code>x3</code>, <code>y3</code>, <code>r3</code> are known.
  I need to solve for <code>a</code>, <code>b</code>, <code>r</code></p>
  
  <p>How to go about doing this in Java? I checked the <a href="http://commons.apache.org/math/userguide/index.html" rel="nofollow">Commons Maths library</a> but didn't find how I could achieve this. It helps with linear equations though.</p>