title: How to get an angle using tangent
body: <p>I have a triangle, knowing lenghts of two sides (see picture) and need to know an angle shown in the picture (red are known, the blue angle is what I need to count)</p>
  
  <p><img src="https://i.stack.imgur.com/Cq1V4.png" alt="enter image description here"></p>
  
  <p>I found out, that Math.Tan gets me the angle expressed in radians, so when I tried to do this: </p>
  
  <pre><code>alpha = Math.Tan((CA/AB));
  </code></pre>
  
  <p>I always get 0 as a result.
  My question is - how can i get this angle, knowing only these two sides?</p>