import pygame
from pygame.locals import *
import sys 

BLACK = (0,0,0)
WHITE = (255,255,255)

screen = pygame.display.set_mode((600, 600))
screen.fill(WHITE)
clock = pygame.time.Clock()

pygame.draw.lines(screen, BLACK, closed=True, points=[(20,90), (400,330), (20,550)], width=5)

while True :
    for event in pygame.event.get():
        if event.type == pygame.QUIT:
            pygame.quit()
            sys.exit()
    pygame.display.update()
    clock.tick(60)