Segment Proofs! D:?

Question

GIVEN: b is the midpoint of AC,
c is the midpoint of BD.
PROVE: AB=CD


Please prove in a two column proof! :D

The diagram is here:
http://img101.imageshack.us/img101/3525/segmentbl4.png

Answer 1

#1 - B is the midpoint of AC - given
#2 - AB ≅ BC - from 1 by def. of midpoint
#3 - C is the midpoint of BD - given
#4 - BC ≅ CD - from 3 by def. of midpoint
#5 - AB ≅ CD - from 2 and 4 by transitivity of congruence