#### Answer

Using method SAS for 2 congruent pairs of sides and 1 congruent pair of included angles, we can prove that $\triangle ABC\cong\triangle DBC$.

#### Work Step by Step

It is given that
- $\overline{AB}\cong\overline{BD}$
- $\angle A\cong\angle D$
- $\overline{AC}\cong\overline{CD}$
We now have 2 sides and the included angle of $\triangle ABC$ are congruent with 2 sides and the included angle of $\triangle DBC$. Therefore, according to method SAS, $\triangle ABC\cong\triangle DBC$.