Space vector is the most commonly used method. Although it is a bit troublesome, it is more available than auxiliary lines. As long as it is made, it should not be given to you. Unless the person who approved it can't understand it, even if he can't understand it, there will be a teacher leader to review it again. Don't worry. If you are not at ease, you can also look at the exam outline of that year, which is very detailed, and then ask the teacher for confirmation.