For every minute you remain angry, you give up sixty seconds of peace of mind.
-Ralph Waldo Emerson
When we get angry we are revealing our shadows. What is a shadow? A shadow is a polar opposite of our egos. In short, what has been repressed by conditioning; such as social conditioning or other forms of it, is held in the shadow where it contradicts and often conflicts with the desires of the ego.
In order to dissolve our anger we need to confront these shadows and work on them. Meditation is one great way to go deep into the unconscious and "bring light upon these dark areas". Once we become aware and work through what triggers such angry emotions the motivation and desire to continue it will dissipate.