Oblicz obwód trójkąta o danych wierzchołkach.
a) A = (3, 1), B = (4, 3), C = (−2, 6)
b) A = (-2,-2), B = (−1, −7), C = (2,-5)
c) A = (-1, -1), B = (–2, 3), C = (3, 1)
d) A = (3, 3), B = (0, 4), C = (0, 0)