import random

def estimation_pi(n):
    dans_le_cercle = 0
    for i in range(n):
        x = random.random()
        y = random.random()
        if x**2 + y**2 <= 1:
            dans_le_cercle = dans_le_cercle + 1
    f = dans_le_cercle / n
    return f * 4