It's National Pi Day, so treat yourself to some pie — pizza, dessert or both, whatever your heart desires! That first "Pi" isn't a typo and differs from the tasty "pie" we eat, though we could easily draw some geometric similarities between the two.

From pizza pies to dessert pies, many businesses and restaurants are offering deals to celebrate Pi Day. Want a slice of the celebration? Here are 10 "irrationally" good deals in the Chicago area.

Friday is March 14, otherwise known as Pi Day thanks to the date's numerical representation lining up with the mathematical constant (3.14).