阅读主函数代码，完成Shape类、Circle类、Rectangle类的定义

Shape类定义：

class Shape:
    def __init__(self, color):
        self.color = color
    
    def get_area(self):
        pass
    
    def get_perimeter(self):
        pass

Circle类定义：

import math

class Circle(Shape):
    def __init__(self, color, radius):
        super().__init__(color)
        self.radius = radius
    
    def get_area(self):
        return math.pi * self.radius ** 2
    
    def get_perimeter(self):
        return 2 * math.pi * self.radius

Rectangle类定义：

class Rectangle(Shape):
    def __init__(self, color, width, height):
        super().__init__(color)
        self.width = width
        self.height = height
    
    def get_area(self):
        return self.width * self.height
    
    def get_perimeter(self):
        return 2 * (self.width + self.height)