def test_error_if_not_figure():
rectangle = Square(4, 2)
with pytest.raises(Exception):
rectangle.add_area(object())
def test_squares_equals_area_after_add_area():
square_1 = Square(4, 2)
triangle_2 = Triangle(6, 2)
assert square_1.add_area(triangle_2) == triangle_2.add_area(square_1)