Question

answer number 13 please............

Answer 1

In triangle OAB and triangle ODC
OA =OC (O is the mid point of AC)
OD =OB (O is the mid point of BD)
Angle AOB =Angle COD (Vertically opposite angles)
Therefore, triangle OAB=triangle ODC (By SAS Congruency)
AB=DC(By cpct)
Hence proved.

Answer 2

I) Yes ∆ OAB congruent to ∆ODC
ii) We ans the above questions by matching these pairs : AO=CO , BO=DO and angle AOB = angle BOC
iii) Yes AB = DC as triangle OAC congruent to triangle ODC , therefore by CPCT we can say this.