How to learn to understand geometry?

Question

Mathematics

This year I finished 11th grade. For the whole school, I only taught mathematics up to grade 7 for 4s, and then I just scored. After I started learning programming, I realized that I like mathematics, technology, etc. I made good friends with algebra, I can think logically, look wider in general. When I began to study trigonometry, I realized that I needed to know at least a little geometry (in particular, triangles and a circle). I read theories, practiced a lot, watched videos on YouTube, from good teachers, but I still can’t get out of these triangles. I just can not understand what and how, for me it is difficult. If there was a person who would show me how geometry works in general, I would understand it.

Are there any tutorials or vids? Tell me please

Answer 1

https://c82.net/euclid/
there is a translated version on github

Answer 2

Linear algebra and analytic geometry (which are used in all practically significant applications of geometry) almost never get into trigonometry, because all the trigonometric nonsense (such as the reduction formula, the sines of a double angle and other tedious cramming), with which the brains of unfortunate schoolchildren are gouged, are hidden there inside vectors and matrices.
That is, all geometry turns into a method of coordinates and vectors, after which everything is reduced to ordinary algebra.
Read university textbooks on linear algebra and analytic geometry, and solve problems.