Question 311409
The diagram is possible only if cd is bd. Let us assume that the actual line segment is bd and that cd is a typo error.

On drawing the diagram we will get two triangles joining at m

Proof:

Proof of congruence of the triangles dem and abm

dm=mb (m is the mid point of db)
em=ma (m is the mid point of ae)
The included angle dem = included angle bma (vertically opposite angles)

Therefore the triangles dem and abm are congruent which means the remaining sides de and ab are also equal.

Angles contained by equal sides are equal
Therefore the angle mde = angle mba

But these are alternate angles
Hence the sides de and ab are parallel to each other (Going by the theorems of paralles lines and the angles formed with an intersecting line)