"Do any of you know about indirect proofs like what I used in this thread. If you've never heard of it, I can show you."

I have a master's in engineering math and computer science - and I've taken many extra math courses - total of maybe 45 credits in math and stats (not including all the physics, EE, and CS courses that used it). Almost half were at the graduate level. I also stay sharp because I tutor geometry every year at the high school level. So, yes, I think it's fair to say that I'm familiar with indirect proofs.