title: How do I find the sphere center from 3 points and radius?
body: <p>I have three 3D points p1, p2 and p3 and the sphere radius. How do I find the sphere center from 3 points and radius?</p>
  
  <p>I expect two 3D points as solution because there are 2 spheres that meet the requirements.</p>
  
  <p>Thanks.</p>