'Returns a dictionary with keys, the vertices of the Polygon,
and values, the interior angle at each vertex.
Examples
>>> from sympy import RegularPolygon, Point
>>> r = RegularPolygon(Point(0, 0), 5, 3)
>>> r.angles
{Point2D(-5/2, -5*sqrt(3)/2): pi/3,
Point2D(-5/2, 5*sqrt(3)/2): pi/3,
Point2D(5, 0): pi/3}'

@property
def angles(self):

    ret = {}
    ang = self.interior_angle
    for v in self.vertices:
        ret[v] = ang
    return ret
