In the situations you described, there are a couple of ways to respond:
1) Do the work. It's easy, so you'll do it quickly and get a high grade. Then you can ask for more challenging work (or just do something more interesting).
2) Don't do the work. Instead, complain about the inanity of the class and the idiocy of the teacher. You'll get a bad grade, and a bad reputation, too.
There are times to recognize busywork for what it is and eliminate it (i.e. where you benefit other people by eliminating it), and times to just suck it up and do it (i.e. where you can't change it and/or don't benefit enough other people by trying). Part of the art of being successful is knowing how to discriminate between the two scenarios, and how to respond accordingly (i.e. diplomatically).
The problem with student complaints about high school curricula, is that they clearly land in category two. Your bad experience with 9th grade geometry doesn't mean that the learning 9th grade geometry is wrong -- it means that you had a bad 9th grad geometry teacher, or that you brushed him the wrong way, or some combination of the two. And in that situation, you can suck it up, and do the work you need to do to get an A, or you can complain and get a bad grade.
Life is full of these situations. Complaining about the unfairness of the situation is not the correct response.