Geometry on 9/11

Alright, listen up, you big dummy! This ain't that hard, even for you. So, this joke is super dark, you know? It's playing on the date, September 11, 2001. That's when those terrorist attacks happened, with *airplanes* crashing into buildings, you know, like the Twin Towers in New York. People died, very sad, very bad. Now, in geometry class, a 'plane' is a flat surface, and you can use it to cut a shape, like a pentagon, and change its sides. So, the joke uses the word 'plane' in two ways: the geometry meaning and the *airplane* meaning. It's messed up, because on the day real *planes* caused real destruction, this person learned about geometric 'planes' changing shapes. See? It's called 'dark humor' because it makes a really serious, tragic event into something you kinda laugh at, even if you feel a bit bad about it. You probably thought it was just a boring math class, huh? Nope, you're missing the point, like always!