Each proof: 1 Mark
In
ΔAOB and
ΔCOD AB=CD [Given]
∠BAO=∠CDO [Alternate angles; as
AB∥CD]
∠ABO=∠DCO [Alternate angles; as
AB∥CD]
(i)
∴ΔAOB≅ΔDOC [A.S.A congruency criteria]
(ii)
AO=DO [Corresponding sides of congruent triangles]
also, (iii)
BO=CO [Corresponding sides of congruent triangles]