python 3类和子类:创建三角形和正方形

我正在自学python类和子类。我想在书上做一个问题,但我被卡住了。我试图创建3个三角形和4个正方形,并打印出一个三角形和一个正方形的所有属性,但我不确定如何创建。谢谢你的帮助!。这本书给了我这个:

> class Shape(object):
>       def __init__(self, corner=10):
>        self.__corner= corner
>        self.__sides=corner

以下是我目前掌握的情况:

class Shape(object):
      def __init__(self, corner=10):
       self.__corner= corner
       self.__sides=corner

  def set_corner(self, corner):
    self.__corner= corner
  def set_sides(self, corner):
    self.__sides= corner
  def get_corner(self):
    return self.__corner
  def get_sides(self):
    return self.__sides

class Square(Shape):
  def __init__(self, corner, area):
    Shape.__init__(self, corner=10)
    self.__area=area
  def set_area(self,area):
    self.__area= area
  def get_area(self,area):
    return self.__area

class Triangle(Shape):
  def __init__(self, corner, height):
    Shape.__init__(self, corner=10)
    self.__height=height
  def set_height(self,height):
    self.__height= height
  def get_height(self,height):
    return self.__height