On 3 accounts have a proved in ONE day that my teacher is a whole lot more stupid that people think she is:
1. Science Fair Project Idea
I had to have my idea okay'd with my teacher, like everybody else's, and it was something simple like how reversing the direction of electricity in an electromagnet affect it (I already knew the answer). When she handed it back, she said, "I have no idea what that means but I know it's right!" (FYI, I am actually the smartest in my class).
2. Angles
My teacher asked us if we could tell if an angle was acute, obtuse, right, or straight just by looking at it, and me and a few others said, "Mostly," because what if it was 89 degrees? My teacher told us to just put a corner of ta paper to check, so I, being the smartass I am, said, "But that's not simply looking at it is it?"
3. Angles, AGAIN
Our teacher asked us what kind of an angle a 0 degree angle is - I said it was a simple ray! She was saying no, but I proved otherwise - a zero degree angle just goes back the way it came from when it reaches the vertex.
TLDR; My teacher is dumb as hell.