Answer:
Statement ∠BCA≅∠DAC
Reason; SSS congruence
Explanation:
Remember each pair of opposite sides of a parallelogram is congruent
Opposite sides are congruent
AD=BC, AB=DC
Using corresponding parts of congruent triangles
∠ACD≅∠CAB and
∠ADC≅∠CBA
Let AC be a transversal for AB and CA then ;
∠ACB ≅∠CAD and ∠ACD≅∠CAB are alternate angles
From the theorem; two lines in a plane are parallel if and only if a pair of altenate interior angles formed by the transversal is congruent as proven above.