Identify the sides or angles that need to be congruent in order to make the given triangles congruent by AAS

In this case, we'll have to carry out several steps to find the solution.
Step 01:
Data:
Triangles
missing angle or side = ?
Step 02:
AAS = angle - angle - side
a. ΔABC Δ DEF
side AB side DE
b. ΔABC Δ DEF
∠A ∠ D
That is the full solution.