title: How to calculate points on upper half of circle
body: <p>I'm trying to place some icons equally on the upper half of a circle.</p>
  
  <p>I managed to place them around a whole circle with the following formula/code</p>
  
  <pre class="lang-cs prettyprint-override"><code>for(int i=0;i&lt;numberOfItems;i++)
  {
      float x = (float)(center.X + radius * Math.Cos(2 * Math.PI * i / numberOfItems))-iconBmp.Width/2;
      float y = (float)(center.Y + radius * Math.Sin(2 * Math.PI * i/ numberOfItems))-iconBmp.Height/2;
  
      canvas.DrawBitmap(iconBmp, new SKPoint(x, y));
  }
  </code></pre>
  
  <p>But I can't figure how to do it for just the upper half of the circle?
  Is there a formula for that as well?
  I have the feeling that the one I have for the whole circle just needs some adjustment to achieve that...but can't figure what.</p>
  
  <p>Thank you already!</p>