Bun. a.) Deci M e mijlocul lui AB => AM = MB. N e mijlocul lui BC => BN = NC. MB + BN = 6. DAR pentru ca MB = AM SI BN = NC => AM + NC = 6. AB + BC = AC = AM + MN + NC = 12 cm.
b.) AM = MB = 2; MN = MB + BN = 5 => 2 + BN = 5 => BN = 3; BN = NC => NC=3. AC = AM + MN + NC = 2 + 5 + 3 = 10 cm.
AB = AM + MB = 2 + 2 = 4
BC = BN + NC = 3 + 3 = 6
c.) AM = 4 => MB = 4
NC = 2 => BN = 2
MN = MB + BN = 4 + 2 = 6
AB = AM + MB = 4 + 4 = 8
BC = BN + NC = 2 + 2 = 4
AC = AB + BC = 8 + 4 = 12