Rhetorical question asked by someone distinctly more cool than whomever is being asked in an attempt to point out his or her inherent corniness or dorkiness.
Is used primarily used by a black person to a white person but may be used by any hip person who wants to call out an uncool subordinate.
Originally used in a skit on Chappelle's Show
"Hey you white guy from Canada, what's the square root of this apartment? (laughs to self)."