'Returns the area.
Examples
>>> from sympy.geometry import RegularPolygon
>>> square = RegularPolygon((0, 0), 1, 4)
>>> square.area
2
>>> _ == square.length**2
True'

@property
def area(self):

    (c, r, n, rot) = self.args
    return (((sign(r) * n) * (self.length ** 2)) / (4 * tan((pi / n))))
