Answer:
Leg-Acute (LA) Angle Theorem.
Explanation:
We can use the postulate Leg-Acute Angle theorem to demonstrate the congruence.
This postulate states "if a leg and an acute angle of one triangle are congruent to the corresponding parts of another right triangle, then those two right triangles are congruent".
So, in this case, we have
, by reflexive property, that is, a segment is congruent to itself.
, by Given.
So, with these two given congruence we demonstrate that
, by Leg-Acute Angle Postulate.
Therefore, the answer is Leg-Acute Angle Postulate.