protected boolean isReflex(Vector2 p0,Vector2 p,Vector2 p1){
  return right(p1,p0,p);
}

protected boolean isReflex ( Vector2 p0 , Vector2 p , Vector2 p1 ) { return right ( p1 , p0 , p ) ; }
returns true if the given vertex , b , is a reflex vertex . < p > a reflex vertex is a vertex who ' s interior angle is greater than 180 degrees .
