It is known that the line segment AB = CD, which coincides with one third of each other, m and N are the midpoint of AB and CD respectively, and Mn = 14cm, the length of AD

It is known that the line segment AB = CD, which coincides with one third of each other, m and N are the midpoint of AB and CD respectively, and Mn = 14cm, the length of AD

Because AB = CD, and they overlap one third of each other
So AB = 3bC, CD = 3bC
So AC = 2BC BD = 2BC
Because m and N are the midpoint of AB and CD respectively
So am = 1 / 2Ab = 3 / 2BC DN = 1 / 2CD = 3 / 2BC
So MC = ac-am = 2bc-3 / 2BC = 1 / 2BC BN = bc-dn = 2bc-3 / 2BC = 1 / 2BC
So Mn = MC + BC + BN = 1 / 2BC + BC + 1 / 2BC = 2BC = 14
So BC = 7
So ad = AC + BC + BD = 2BC + BC + 2BC = 5BC = 35cm