Python（1）分别定义 3 个类：Triangle、Rectangle 和 Circle，这 3个类的方法为 Area()和 Perimeter()

Python（1）分别定义 3 个类：Triangle、Rectangle 和 Circle，这 3个类的方法为 Area()和 Perimeter()

import math

class Triangle():
    def __init__(self,a,b,c):
        self.a = a
        self.b = b
        self.c = c

    def Area(self):
        p = (self.a+self.b+self.c)//2
        return math.sqrt(p*(p-self.a)*(p-self.b)*(p-self.c))

    def Perimeter(self):
        return self.a+self.b+self.c


class Rectangle():
    def __init__(self,a,b):
        self.a = a
        self.b = b

    def Area(self):
        return self.a*self.b

    def Perimeter(self):
        return (self.a+self.b)*2

class Circle():
    def __init__(self,r):
        self.r = r

    def Area(self):
        return math.pi*self.r**2

    def Perimeter(self):
        return math.pi*self.r*2

triangle = Triangle(3,4,5)
print(triangle.Area(),triangle.Perimeter())

rectangle = Rectangle(3,4)
print(rectangle.Area(),rectangle.Perimeter())

circle = Circle(3)
print(circle.Area(),circle.Perimeter())