Type SSS, SAS, ASA, SAA, or HL to
justify why the two larger triangles are
congruent.

HL

Explanation: The HL Postulate states that if the hypotenuse and leg of one right triangle are congruent to the hypotenuse and leg of another right triangle, then the two triangles are congruent.

And in your triangles the hypotenuse legs are congruent (the hypotenuse is the largest side of the triangle) and the other part that is congruent is the middle leg because they are sharing that leg.

Hope this explanation helps you :D