ASA
Explanation:
It might help to peel the triangles apart as I have done so below.
We have two pairs of congruent angles, as shown by the distinct angle markers. Between the congruent angles, we have a pair of congruent sides.
The side (S) is between the angles (A), which is why we use ASA.
Note: SAA is slightly different where the congruent sides are not between the congruent angles.
![Type SSS, SAS, ASA, SAA, or HL to
justify why the two larger triangles are
congruent.](/tpl/images/1379/6538/a3ffc.jpg)