Bài 3:
from math import sqrt
from math import pow
def distance_points(ax, ay, bx, by):
return sqrt(pow(bx - ax, 2) + pow(by - ay, 2))
x1 = int(input())
x2 = int(input())
x3 = int(input())
y1 = int(input())
y2 = int(input())
y3 = int(input())
dab = distance_points(x1, y1, x2, y2)
dbc = distance_points(x2, y2, x3, y3)
dac = distance_points(x1, y1, x3, y3)
print("d_AB = {:.3f}".format(dab))
print("d_BC = {:.3f}".format(dbc))
print("d_AC = {:.3f}".format(dac))