title: Calculate Earth convex hull polygon area given latitude and longitude
body: <p>I have searched for explanations and algorhitms how to calculate Earth's polygon surface area. I've found <a href="http://answers.yahoo.com/question/index?qid=20080213175333AASYvUd" rel="nofollow noreferrer">this</a> and <a href="https://stackoverflow.com/questions/4681737/how-to-calculate-the-area-of-a-polygon-on-the-earths-surface-using-python">this</a><br>
  Lets say I got already convex hull points<br>
  <code>[56.992666,24.126051], [58.00282,25.930147], [58.787955,25.565078], [59.4997,24.861427], [59.463678,24.711365], [59.395767,24.599837], [56.992666,24.126051]</code></p>
  
  <p>From second link the first answers uses Python library and second answer approach won't give quite precise area even if we assume that Earth is sphere (am I right)?
  What approaches could I take for calculating the area (less expensive) if we assume that Earth is sphere?</p>
  
  <p>In addition, I have looked for different libraries (geotools.org etc) but haven't found in their documentation about area calculation.</p>