Hey there!
The answer to 1. Is VR and TS. The answer to 2. Is VR and SR because of the mark in the corner which means that the angle is 90 degrees. This always means that the two lines that are making the 90 degree angle are perpendicular. The answer to 3. Is TV and RV because there’s no 90 degree angle and the lines are crossing each other if the lines would go on forever in both directions.
I hope this helps!