Inspired by a quote from C.S. Lewis. Though C.S. Lewis was a Christian writer, I love that Buddhism also teaches us that when we get angry, we are in fact suffering immense pain.
Anger in itself is neither good nor bad. It is simply a form of energy, and like all energies, can be transformed. If we sit with our anger long enough to get to know it and the sorrow inherent to anger, it can show us the way to transform it into positive action.