title: Find the New Position of Vertices Given a Rotation Matrix
body: <p>I have two triangles facing in arbitrary directions. I have the forward vector for both triangles, and I want to align each of the forward vectors to face the same direction. I only have the ability to do rotations about the world x, y and z axis (The software API I am using is very limited).</p>
  
  <p>So, let A = forward vector of the first triangle, and B = forward vector of the second triangle.
  I am able to find the Rotation Matrix using this equation:</p>
  
  <pre><code>v = B X A
  s = ||v||
  c = A dot B
  
  vx = skew-symmetric cross-product matrix of v
  
  R = I + [vx] + [vx]^2 * (1-c)/s^2
  </code></pre>
  
  <p>I am able to find R.</p>
  
  <p>I am not sure how to use R so that I can move the vertices of triangle B such that the triangle B and triangle A are facing in the same direction.</p>
  
  <p>Picture for Reference:</p>
  
  <p><img src="https://i.stack.imgur.com/eKWVN.png" alt="enter image description here"></p>
  
  <p>Thank you all in advance for the help.</p>