Answer:
1. RQ
2. R, Y and V
3. T
4. No
Step-by-step explanation:
If we imagine a plane as a rectangle, we can easily see that planes RSTQ and RVUQ intersect in line RQ. Basically, if two planes intersect each other, that intersection is always a line.
Collinear points lie on the same line. Every two points make a line, so the third one also needs to lie along that line. On the diagram, R, Y and V are the only three points on the same line.
From the diagram, we can infer that QT and TX intersect in point T. Additionally, every two lines intersect in a point (of course, unless they're parallel).
Coplanar points lie in the same plane. Three points are enough to define a plane. Whichever three points (R, Q, W and U) we choose we'll have a plane, but the fourth point won't lie in it. This means they are not coplanar.
