First of all, it is easy to do this problem with junior high school knowledge. It is not difficult to prove the congruence of the triangle (AAS) by making the vertical lines on both sides of the point O, and it is not difficult to find the second problem by splitting it in two from the vertical foot.

Parabolic high school introduced the concepts of focus and directrix. However, the parabola of analytic geometry in high school often has its vertex at the origin, and it will be solved by combining ellipse and hyperbola.

Trigonometric function is sine and cosine theorem, double angle formula, and another example is asinA+bcosA=√(a? +b？ ) sin(A+ψ), where tan ψ = b/a.

In addition, there are vectors, complex numbers, series, mean inequality, monotonicity and parity of functions and so on. ....

These things may not make junior high school questions easy, but there may be some questions that can make solving problems easy.

Off-topic: Although the compilation of teaching materials is not completely reasonable, it is certainly feasible. Judging from what you said, your grades are not bad, and it is no problem to meet the requirements of junior high school mathematics textbooks. Don't ask yourself to master high school knowledge in advance. Of course, it's good to have extra energy to know something about high school, but don't force yourself, put too much pressure on yourself and step by step.

I am not an educator, and the above remarks may not be correct, for reference only.