Look at the class notes first. You don't need a formula to do math. It is mainly a matter of concept. If you don't have any ideas when doing the questions, you can sort out your notes in the class after school and try to classify the questions that the teacher has done by himself. For example, geometry, the center line is doubled, and the auxiliary line is added. Sort it out more, and you will have a little feeling about the topic. Further, you will find that you can do most of the questions as long as you understand the ideas. Then, you will start to sum up your thoughts and sort out all the inspirations in your problems, and you will find many problems. Try to prove them yourself and make your own special formula to do the last question. Come on (this is a hard process, but I believe that since you can ask questions here, you will have the perseverance to stick to it. Come on! )