# The original class
class Triangle:
    
    def __init__(self, height, width):
        self.height = height
        self.width = width

    @property
    def area(self):
        return 0.5 * self.height * self.width

# The new class
class Triangle(Triangle):
    
    def __mul__(self, value):
        return Triangle(self.height*value, self.width*value)
    
    def __lt__(self, other):
        return self.area < other.area
    
    def __repr__(self):
        return f'{self.__class__.__name__}(height={self.height}, width={self.width})' 

import math
class Point:

    def __init__(self, x, y):
        self._x = x
        self._y = y
        
    def distance_to(self, other):
        '''Return the distance to another point instance.'''
        x0, y0 = self._x, self._y
        x1, y1 = other._x, other._y
        return self.distance(x0, y0, x1, y1)
    
    @staticmethod
    def distance(x0, y0, x1, y1):
        return math.sqrt( (x1-x0)**2 + (y1-y0)**2 )

class Polyline:

    def __init__(self, points):
        self.points = points
    
    def __len__(self):
        return len(self.points)-1
    
    def get_total_length(self):
        length = 0
        for point0, point1 in zip(self.points, self.points[1:]):
            length += point0.distance_to(point1)
        return length

pt1 = Point(0,0)
pt2 = Point(0,5)
pt3 = Point(5,5)