Answer:
The proof is shown below.
Explanation:
Given: B is mid point of AC and C is mid-point of BD.
To prove: AD=3AB
It is given that B is mid-point of AC.
⇒ AB = BC ...(1)
Also, C is mid-point of BD.
⇒ BC = CD ...(2)
From (1) and (2),
AB = BC = CD
Now, AD = AB + BC + CD
⇒ AD = AB + AB + AB (∵ AB = BC = CD )
Hence proved.