What is 1 half of a pie?

'pie' is the food that you eat , such as Apple pie, or meat pie.

However, I think you mean 'pi' Note the spelling.

'pi' is the small case letter 'p' from the Classical Greek Alphabet, and refers to ( the constant of ) 'proportion' , that is the proportion between a circles circumference and its diameter.

C = pi*d

pi is an irrational number, which means the decimal digits go to infinity, AND are not in any regular order.

However, for everyday school/working purposes , pi = 3.1416

So half a 'pi' is pi/2 = 3.1416/ 2 = 1.5708