// Convert an angle in degrees to radians.
#include <iostream>
using namespace std;

// prototypes
double rad(double);

int main () {
  double degrees, radians;
  cout << "Input the angle in degrees: ";
  cin >> degrees;
  radians = rad(degrees);
  cout << degrees << " Degrees = " << radians << " Radians." << endl;
}

double rad(double x) {
  const double pi = 3.14159265358979323846;
  return x*pi/180;
}