Is ABC = def if so name the postulate that applies

Might not be congruent.

Step-by-step explanation:

In the given figure, we have two right triangles ΔABC and ΔDEF.

Also, it is given that,

So by, AAA similarity rule we can say  ΔABC and ΔDEF are similar.

But we cannot say it is congruent.

We need at-least one side equal in both triangles to prove it congruent.

For example :-All the equilateral triangles are similar but not congruent as the side lengths vary as per triangle but the angles remain same  .