EXPLANATION
Statement Reason
AD ≅ CB Parallel opposite sides of a parallelogram are congruent
DC ≅ BA Parallel opposite sides of a parallelogram are congruent
DB ≅ BD Reflexive Axiom
△DAB ≅ △BCD Side-Side-Side Theorem
Reflexive Axiom: Any figure with a measure of some sort is also equal to itself. In other words, segments, angles, and polygons are always equal to themselves.
