Similar Triangles
In similar triangles, the ratio of all the corresponding side lengths is the same.
If we wanted to prove triangle STU is similar to triangle WVU, then the corresponding sides are:
ST and WV
TU and VU
SU and WU
If both triangles are similar then the following ratios should be equal:
ST/WV = TU/VU = SU/WU
The three first choices express the very same proportions. All of these options are correct.
Choice D states that triangle STU is congruent to triangle SUT. It does not prove similarity between the two given triangles.
Thus, the only correct choices are A B C