Answer
Proof 1:
$\overline{AB}$ is congruent to $\overline{CD}$ and $\overline{AD}$ is congruent to $\overline{CB}$ because it is given in question.
Proof 2:
$\overline{AC}$ is identity
Proof 3:
$\triangle$ABC ≡ $\triangle$CDA is given in question
Work Step by Step
Given:
$\overline{AB}$ is congruent to $\overline{CD}$
$\overline{AD}$ is congruent to $\overline{CB}$
To prove:
$\triangle$ABC ≡ $\triangle$CDA