class Polygon:
def sides_no(self):
pass
class Triangle(Polygon):
def area(self):
pass
obj_polygon = Polygon()
obj_triangle = Triangle()
print(type(obj_triangle) == Triangle) # true
print(type(obj_triangle) == Polygon) # false
print(isinstance(obj_polygon, Polygon)) # true
print(isinstance(obj_triangle, Polygon)) # true