import time
from tkinter import *

tk = Tk()
canvas = Canvas(tk, width=400, height=400)
canvas.pack()
canvas.create_polygon(10,10,10,60,50,35)

for x in range(0,60):
	canvas.move(1,5,5)
	tk.update()
	time.sleep(0.05)
	
for x in range (0,60):
	canvas.move(1,-5,-5)
	tk.update()
	time.sleep(0.05)

tk.mainloop()