• # question_answer 6) If B is the mid-point of $\overline{AC}$ and C is the mid-point of $\overline{BD}$, where A, B, C and D lie on a straight line, say why AB = CD ?

Given, B is the mid-point of $\overline{AC}$. AB = BC ...(i) and C is the mid-point of $\overline{BD}$. $\therefore$ BC = CD ...(ii) i.e. Now, on adding Esq. (i) and (ii), we get AB + BC = BC + CD AB = CD Hence proved.