He divorced his wife before consummating the marriage and he does not know what he said because he was so angry
If a man does the shar‘i marriage contract with a woman, then he divorces her, it counts as a divorce, whether he consummated the marriage with her or not, and whether the marriage was registered with the authorities or not.
But if, as you say, you spoke the word of divorce when you did not know what you were saying because of severe anger, then it does not count as a divorce.
We have previously discussed the issue of divorce in a state of anger, and what counts as divorce and what does not in such cases, in the answer to question number 45174.
You should beware of using the word of divorce (talaaq) and avoid it in all situations, especially since you are at the beginning of your married life, because this is something which will make the wife afraid and anxious, and it could lead to separation between you in ways you do not want.
We ask Allah to guide us and you.
And Allah knows best.