Hello, my friend, I'm a fitness instructor. I'm happy to answer your question. I feel this is a physics problem, but I know the answer can be answered for you. As long as you aim at the black ball in the mirror (the black ball aims at the B mirror in the A mirror), as long as the straight line sends enough force to overcome the resistance, you will definitely hit the black ball at any angle.

If you have any fitness questions, you can ask this fitness instructor to answer them.