is Pi a predefined variable in c++ code example
Example: pi in c++
#define _USE_MATH_DEFINES // must include this!
#include <cmath>
#include <iostream>
int main() {
// M_PI = 3.14159265358979323846;
std::cout << M_PI << " " << M_E << " " << M_SQRT2 << endl;
return 0;
}