(Homer tries to retrieve the angry letter that Bart accidentally put in the mail.) Homer: Hello, my name is Mr. Burns. I believe you have a letter for me. P.O. Worker: Okay, Mr. Burns. What's your first name? Homer: I...don't know.
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!