Answer: SSS similarity postulate
Explanation:
The SSS similarity postulate says that if the lengths of the corresponding sides of two triangles are proportional then the triangles must be similar.
In the given figure , we have two triangles ΔABC and ΔXYZ such that the corresponding sides of both the triangles are proportional.
i.e.

Then by SSS-similarity criteria , we have
ΔABC ≈ ΔXYZ