Relative and absolute drawing of pentagram using turle

pentagram.py

from math import sin, radians, cos

from python.common.Turtle import Turtle
from python.less2.combinatorics import combinations


def pentagram_relative(size=100):
    t = Turtle()

    t.forward(size)
    for i in range(5):
        t.right(360 / 5)
        t.forward(size)

    t.left(180 / 5)
    lengh = 2 * sin(radians((180 - 360 / 5) / 2)) * size
    print(lengh)
    for i in range(5):
        t.right(180 - (180 / 5))
        t.forward(lengh)
    t.export("pentagram_relative")


def ngram_abs(n=5, size=100):
    t = Turtle()
    angle = radians((360 / n))
    corner_points = [(cos(i * angle) * size, sin(i * angle) * size)
                     for i in range(n)]

    first_p = corner_points[0]

    t.penup()
    t.goto(first_p)
    t.pendown()

    for p in combinations(corner_points, 2):
        t.goto(p[0])
        t.goto(p[1])

    t.export(str(n) + "-gram_abs")


pentagram_relative(600)
ngram_abs(7, 600)