Given: a ∥ b and ∠1 ≅ ∠3Prove: e ∥ fWe know that angle 1 is congruent to angle 3 and that line a is parallel to line b because they are given. We see that __________ by the alternate exterior angles theorem. Therefore, angle 2 is congruent to angle 3 by the transitive property. So, we can conclude that lines e and f are parallel by the converse alternate exterior angles theorem.Which information is missing in the paragraph proof?