Second, when you are irritated by sb, you can say I am angry with sb; when you are irritated by sth, you can say I am angry at/ about sth.
Generally, be angry at sth has the same meaning with be angry about.
Howerver, in the following example, about can not be replaced by at
Ex:(1) She was angry about his laughing at her.
Because here to use about to avoid the repeat of at.
In addition, be angry at is focusing on people's behavior.
Ex: I was angry at his slipshod work.
If you want to express you are very very angry with sb, you can also say be angry at sb.
Ex: We were angry at the boys for their tardiness.
As for angry over, I know nothing about it.
Hope it helps.
[not a native]
Student or Learner