Ouch. That happened to me when I was much younger. In year 5, we were given an assignment to research and make a book about Antarctica. So i spent a lot of time writing it neatly, decorating and colouring a 10 page handwritten A4 book. Which was a lot for a 10 year old kid. I was doing last minute research to finish off my assignment and read that you could swim in antarctica. Yep. And tired, naive little me went and wrote that down. My teacher shamed me in front of our whole class and I burst into tears because I worked really hard on it. I still have it though...

that's very unprofessional. my professor shares funny answers (like where the student has completely given up and just started drawing random shit) but doesn't make fun of people for being stupid.

Talk to the principal, because that's illegal and that will get him fired