Question

how can triangles be proven similar by the SSS?

Answer 1

If all angles are equal then then they are SSS theorem

Answer 2

What is the ratio UV/XY?  50/40 = 5/4
What is the ratio WU/ZX?  40/32 = 5/4
What is the ratio WV/ZY?  60/48 = 5/4

Since all of these ratios are the same, Answer A is correct.