"$pringfield (or, How I Learned to Stop Worrying and Love Legalized Gambling)"

Season 5 / Episode 10 (2:28)

THE SUM OF THE SQUARE ROOTS OF ANY TWO SIDES OF AN ISOSCELES TRIANGLE...

IS EQUAL TO THE SQUARE ROOT OF THE REMAINING SIDE.

THAT'S A RIGHT TRIANGLE, YA IDIOT! D'OH!