#### Answer

1. Given
2. corresponding angles are congruence
3. vertical angles are congruence
4.m $\parallel$n
5. Corresponding angles are congruence
6.$\angle$1 $\cong$ $\angle$ 4, transitive properties proven

#### Work Step by Step

1. Given
2. As l and m are parallel then $\angle$1 and $\angle$2 that is corresponding angles are congruence
3. all vertical angles are congruence. Therefore $\angle$2 and $\angle$3 are congruent
4. the given statement is m $\parallel$ n
5. As m and n are parallel then $\angle$3 and $\angle$4 that is corresponding angles are congruence
6.by using transitive properties we can prove that $\angle$1 $\cong$ $\angle$ 4