title: Get the angle from a rotated matrix using glm?
body: <p>I want to know how to get the angle from a rotated matrix, how do I calculate that? I am using glm c++.</p>
  
  <p>For example
  how do I get the angle from this matrix using c++?</p>
  
  <pre><code>[-0.01458][-2.26652][0][0]
  [-1.27492][-0.02596][0][0]
  [    0   ][    0   ][1][0]
  [    x   ][    y   ][z][1]
  </code></pre>