What to read to learn how to solve problems on a plane?

Question

Mathematics

When passing the entrance exams, there will be problems like this: 2 parallel planes are given, there is a point that does not lie on these planes, 2 straight lines are drawn through it, so that the straight lines intersect the planes at some different points ... then the lengths of some segments are given and you need to find the length some unknown segment. Something like.
There will be about 30% of such tasks. And I can't decide at all. I do not represent from what topic these tasks.
Please tell me materials, videos, articles, etc. that will help you understand these tasks and with which you can learn how to solve them.
Thank you.
PS. Here is one of the tasks:

Answer 1

• Two intersecting lines define a plane.
  So the problem is reduced to two similar triangles in the plane, which also have two parallel faces, because are part of those || lines at the intersection of planes.
  To learn how to imagine voluminous tasks, first try to simulate conditions “on your fingers”: a table or a sheet of paper is a plane, two pencils are parallel segments sticking out of it somewhere upwards, maybe at an angle. On one pencil from the plane 8 cm, on the other 6 - these are points C and D.
  Another option, more difficult, is to use a program, for example, GeoGebra - and there simulate the conditions of the problem and “spin” around the model.
  From the two given conditions of the problems, it can be seen that so far this is not complex stereometry, but problems that reduce to geometry on a plane.

Answer 2

You just need to learn to imagine the conditions in your head.
In the given condition, a triangle and a trapezoid at its base are obtained.
It is difficult for some people to imagine (it is not clear why - probably problems with the brain) - in this case, one must immediately abandon the technical path of education.