I would say XYZ~RQS (The third picture)
Since the proportions need to be the same for each pair of corresponding sides, you can see that
.
In which all the ratios are equivalent to
.
Thus, XY corresponds to RQ, YZ corresponds to QS, and ZX corresponds to SR. So, XYZ~RQS.
If there is anything unclear about this explanation, please do tell me, as I'm not very good at explaining.
Have a great day!