How the pi function is used in c++???

Question

pi function comes in math.h heading

Answer 1

we all know PI to be 22/7 which results to 3.142 when rounded up to 3 decimal places.

In your code, just define PI and you are set to go.

example
#define PI 3.142

you can also make it a constant since PI doesnt change.

Answer 2

how it works??