'Measure of the interior angles.
Returns
interior_angle : number
See Also
sympy.geometry.line.LinearEntity.angle_between
Examples
>>> from sympy.geometry import RegularPolygon, Point
>>> rp = RegularPolygon(Point(0, 0), 4, 8)
>>> rp.interior_angle
3*pi/4'

@property
def interior_angle(self):

    return (((self._n - 2) * S.Pi) / self._n)
