Classmate, I recalled that the fixed value problem generally refers to the fact that in a moving graph, the length of a segment is constant, or the length is an integer multiple of a segment.

This kind of problem usually appears in the second or third question of the last three questions in the exam. Generally speaking, it is more difficult, and it depends on your own level when you do it. After all, there is a time limit for exams.

This kind of problem, usually through the rotation, construct congruent triangles, move an edge to other places. Of course, there are still a few numerical values derived by similar triangles and Secant Theorem.

This kind of problem. . . No matter how much I say, you still have to read more to make it. Send me a hi message or ask for help, whatever.

Also, email victor _ zhw @126.com.