how to make turtle shape image smaller

1from turtle import *
2color('red', 'yellow')
3var = 100
4
5begin_fill()
6while True:
7    forward(var)
8    left(170)
9    if abs(pos()) < 1:
10        break
11end_fill()
12
13done()
14

1from turtle import *
2color('red', 'yellow')
3var = 450 # bigger !!!
4
5begin_fill()
6while True:
7    forward(var)
8    left(170)
9    if abs(pos()) < 1:
10        break
11end_fill()
12
13done()
14

1# start a turtle document:
2import turtle
3t = turtle.Turtle()
4# set turtle's opacity to 50, or 50% transparency.
5t.setfillopacity(50)