Welcome to the world of Sarcastic Math, where we prove theorems by certainty.
Today's lesson: Proof by Certainty.
In this esteemed institution, we've managed to prove the Pythagorean Theorem using nothing but certainty. It's not like we actually had to do any math.
Here's the "proof": A² + B² = C², because we're pretty sure it's true.
That's it. You're welcome.
Examples of other proofs by certainty, because who needs rigor, anyway?