Step-by-step explanation:
1. 
(chain rule)
2 
Answer:
a pair of corresponding sides must be shown congruent
Step-by-step explanation:
The triangles are "similar" if corresponding angles are congruent. The triangles will only be "congruent" if corresponding sides are also congruent. The additional information needed is that <em>there is one congruent pair of corresponding sides</em>. (If there's one pair, all pairs of corresponding sides will be congruent.)
Having one pair of corresponding sides congruent would allow you to invoke either of the ASA or AAS congruence postulates.
