No, I'm not forgetting an "e" at the end of "pi", but it would certainly be an appropriate and fun way to celebrate Pi Day with a circular fruit pie or pizza pie!
"Pi" or "π" is the math constant that is the ratio of a circle's circumference to its diameter, or approximately 3.14. Remember that the circumference of a circle is the measurement of the perimeter, or outside, of the circle, and it's diameter is the length across the widest part of the circle.
National Pi Day is thus celebrated on March (3rd month) 14. Will you be celebrating Pi Day this year?