class Point(object):
     def __init__(self, x, y):
         self.x = x
         self.y = y

     def __sub__(self, other):
         return Point(self.x - other.x, self.y - other.y)

     def __add__(self, other):
         return Point(self.x + other.x, self.y + other.y)

class Line(object):
     def __init__(self, p1, p2):
         self.p1 = p1
         self.p2 = p2

     def angle(self):
         v = self.p2 - self.p1
         length = math.sqrt(v.x * v.x + v.y * v.y)
         s = v.y / length
         c = v.x / length
         return math.atan2(s, c)

   function angleDetect(x1, y1, x2, y2) {
   var dx = x2-x1;
   var dy = y2-y1;
   return Math.atan2(dy, dx)*180/Math.PI;
   }