def test_error_if_not_figure():
rectangle = Rectangle(5, 2)
with pytest.raises(Exception):
rectangle.add_area(object())
def test_rectangles_equals_area_after_add_area():
rectangle_1 = Rectangle(5, 2)
triangle_2 = Triangle(6, 3)
assert rectangle_1.add_area(triangle_2) == triangle_2.add_area(rectangle_1)