March 14, or is known as “ Pi Day ” because of its resemblance to the first three τ (tau), is equal to 2 π, so π is 1 2 τ —and March 14 is thus Half Tau Day.
Today, on what's usually called “ 2 Pi Day ” (do you bake twice as many pies as you usually would?) we're seeing headlines about “pi being.
Pi Day is an annual celebration of the mathematical constant π (pi). Pi Day is observed on Contents. [hide]. 1 History; 2 Observance; 3 See also; 4 References; 5 External links Mar. Ultimate Pi Day, Pie Day! Part II