Homer: (Wearing glasses) The sum of the square roots of any two sides of an isosceles triangle is equal to the square root of the remaining side! Man: (From inside a bathroom stall.) That's a right triangle, you idiot! Homer: D'oh!
Bart: Boys and girls, Mrs. Krabappel, I come before you today to solve a riddle that has plagued mankind for centuries: What has four legs and ticks? Milhouse: A walking clock? Nelson: A walking clock! Martin: I'd wager he has some variety of walking clock in that box! Edna: Bart, is it a walking clock? Bart: What?.....No, it's my dog.