Triangle Trian(int, int, int, int, int, int);
Triangle Trianpt(Point, Point, Point);
Point centroid(Triangle);
void triangle(Image *, Triangle, int, Image *, Point);
void filltriangle(Image *, Triangle, Image *, Point);
Triangle rotatriangle(Triangle, double, Point);
Vector Vec(double, double);
Vector Vpt(Point);
Vector addvec(Vector, Vector);
Vector subvec(Vector, Vector);
Vector mulvec(Vector, double);
double dotvec(Vector, Vector);
Vector normvec(Vector);
double round(double);
Point rotatept(Point, double, Point);
int ptincircle(Point, Point, double);
int triangleXcircle(Triangle, Point, double);
void *emalloc(ulong);