Answer
$\triangle$DEF is congruent to $\triangle$ABC by SAS and CPCTC.
Work Step by Step
1.It is given the $\overline{EF}$ is congruent to $\overline{AB}$.
2.It is also given that $\overline{DF}$ is congruent to $\overline{AC}$.
3. Since they are vertical angles $\angle$2 is congruent to $\angle$3 by the Vertical Angles Theorem.
4.It is given that $\angle$1 is congruent to $\angle$2.
5. To to number 4 and 5, we can conclude that $\angle$3 is congruent to $\angle$1.
6.Now that we have 2 sides and the angle between them, we can conclude that $\triangle$DEF is congruent to $\triangle$ABC by SAS.
7.Since Corresponding Parts of Congruent Trianles are congruent, $\angle$B is congruent to $\angle$E.