Question

angle AOC=angle ACO and angle BOD=angle BDO. Prove that AC is parallel to DB

Answer 1

aoc= aco (given) -(1 )
aoc= bod (vertically opp angles) -(2)
bod=bdo (given)
from 1 and 2
aoc=bod
aoc and bod form alternate interior angles
therefore a.c. is parallel to db
hence proven

Answer 2

Answer is
Angle AOC=ACO (Given)
, , AOD = COB (alternate angle)
, , BOD= BDO (given)
Hence, AC II DB