#include <math.h>

typedef  long int dist;  // in mm
typedef  int angle;      // in degrees

// rebuild angle units to anything you want  - this is for degrees

#define fromRads(A) (A)*(180/M_PI)
#define toRads(A)   (A)*(M_PI/180)

#define sqr(A)      (A)*(A)    


dist dist3d(dist p1x, dist p1y, dist p1z, dist p2x, dist p2y, dist p2z);
angle elbow(dist C, dist A, dist B); // returns angle c
angle dir(dist x, dist y);