In this case, we'll have to carry out several steps to find the solution.
Step 01:
Data
Diagram
Step 02:
We must apply the properties of parallel and transversal lines.
Statements Reasons
AB || CD , AB = CD 1. Given
∠ ABD = ∠ CDB 2. Alternate interior angles
BD = DB 3. Reflexive Property
ΔABD = ΔCBD 4. Side-angle-side SAS
That is the full solution.