>>347
that is indeed an excellent resource, thank you. But I'm looking for something easier and more beginner friendly, since Chen's books are meant for people who already have an aptitude for solving olympiad level geometry problems. My cousin has not encountered proofs and critical thinking yet, since he's studied high school level mathematics, which incentivizes memorization over grasping concepts. Also, as you might have guessed, we're not native english speakers, so foreign authors can be a bit tough to understand sometimes. I bought him the AOPS vol1 and vol2 books, since they seem like a good starting point for a kid with no priot experience with math contests, and I'd appreciate more recommendations in the same vein as those.
This is kinda unrelated, but he also has this problem of not having a large enough attention span to sit through books and grasp information from them, and he tends to gravitate towards video lectures and spoonfeeding to get his concepts cleared. I find this very concerning, and would like advice on how to make him understand and use books/the internet instead of his zoomershit. I've made accounts for him on a couple of math forums(AOPS,Math stack exchange) and made reddit,discord and telegram accounts to join doubt clearing spaces/servers/subs. Hopefully that will help him get his doubts cleared rather than relying on the substandard teachers that he currently has.