title: How to find clockwise angle in degree between two vector in java
body: <p><img src="https://i.stack.imgur.com/4YpL5.png" alt="All vector"></p>
  
  <p>First I want to call this following vector as:</p>
  
  <p>Vector M1 = [O → M1];
  Vector C1 = [O → E];</p>
  
  <p>Vector M2 = [A → M2];
  Vector C2 = [A → C];</p>
  
  <p>Vector M3 = [B → M3];
  Vector C3 = [B → G];</p>
  
  <p>every M vector is main vector or base vector.</p>
  
  <p>My problem is how to find angle between those vector(M to C). to decide which direction did C look compare from M.</p>
  
  <p>e.g.</p>
  
  <p>1.) M1 and C1 direction is right.</p>
  
  <p>2.) M2 and C2 direction is left.</p>
  
  <p>3.) M3 and C3 direction is back.</p>
  
  <p>ps. sorry for my bad English, if you don't understand what I try to say, ask me.</p>
  
  <p>Edited:
  angle should be in clockwise direction.</p>