Ranting about the adults I encounter

Okay so basically I was at school right and my friend and I had just a little disgareemnt that pissed me of. So in comes the teacher and I'm in the process of trying to calm down and he's talking or whatever and I was like "What?" and I'm still annoyed so obviously I sound it and repeated himself so I nodded my head yes, but he gives me this dumb look and is like "I don't understand what your saying" so obviously I'm confused and I say what again and he's immediately like "I asked you a question" and I was like "Yeah I know I nodded my head yes" and he's like "I don't get why you have an attitude" and my friend is agreeing with him and its like bro stfu you're the reason why I have an attitude and then he just storms off. The thing I don't understand is why tf would he continue to talk to me if he clearly sees that I'm angry. It's not like he was trying to help he was just continuing to piss me off