Answer:
SSS postulate
Explanation:
Suppose there exist two right triangles ΔABC and DEF right angled at B and E, in which their corresponding hypotenuse and one leg are equal.
i.e. AC=DF and AB=DE
Then, by using Pythagoras theorem, we can conclude that

Thus, ΔABC ≅ DEF, by SSS postulate
Thus, The HL congruence theorem for right triangles is a special case of the SSS postulate.