If we do get angry (and we should try not to) we should not sin

We should try not to get angry.  Anger is a secondary emotion that is usually triggered by some need or expectation not being met.  When something doesn't go the way we would like, we can get angry.  If we do get angry we should be very cautious in what we say and do.  Because it is at such a time that we can do something that we will later regret.  If we are angry, we should deal with what's causing the anger.  Remember this, it is always helpful to learn from every situation and go easy on others. (Psalms 4:4)