A hillbilly family’s only son saves up money to go to college. After about three years, he comes back home. They are sitting around the dinner table, when the dad says, ”Well son, you done gone to college, so you must be pretty smart. Why don’t you speak some math fer’ us?” ”Ok, Pa.” The son then says, ”Pi R squared.” After a moment, the dad says, ”Why son, they ain’t teached ya nothin’! Pie are round, cornbread are square.”