#include <stdio.h>
#include <math.h>

double lookingForSide(double degrees, double side);

void main() {
    double degrees = 5, side = 2;
    printf("ABC %.2lf, AB %.2lf. result is a %.2lf", degrees, side, lookingForSide(degrees, side));
}

double lookingForSide(double degrees, double side) {
    double radianSide = degrees * M_PI / 180.0;
    return side / cos(radianSide);
}