In the equation a = πr², π (pi) is a _____________

π(pi) is an irrational number whose value in fractional form is 22/7 which is usually approximated to the value of 3.14

Answer: In the equation a = πr², π (pi) is a numerical constant. 

The value of π is always a constant. Pi value approximated to 6 decimal places is: π = 3.141593. π is an irrational number.

Thus, in the equation, a = πr², π (pi) is a numerical constant.