What statement is used to prove that quadrilateral ABCD is a parallelogram?

Angles BAD and ADC are congruent.

Corresponding angles BCD and CDA are supplementary.

Sides CD and DA are congruent.

Vertical angles BPA and DPC are congruent.

Question

What statement is used to prove that quadrilateral ABCD is a parallelogram? 

 Angles BAD and ADC are congruent. 

 Corresponding angles BCD and CDA are supplementary. 

 Sides CD and DA are congruent. 

 Vertical angles BPA and DPC are congruent.

anonymous · Answer

jadeishere · Answer

angles BAD and CDA are congruent, I believe

anonymous · Answer

@Jadeishere  could you show me how you got that

jadeishere · Answer

Just take a look at the angles.  if you were to flip it around to DAB and CDA it would be the same angle

anonymous · Answer

ohh okay +  
                    D
                +

anonymous · Answer

i think its the last statement