The problem in question is C, the photo. if you can, please help me. sorry if i worded that wrong. i just got up and i hate math in the morning. -_-

Does anyone know what the m in front of the ∠s mean? (like m∠m, that one is the most confusing since there was 2 m's to begin with.) and if you could, please give me an example of how to solve it? it doesn't have to be one of the problems on it, unless you want to, that's fine too. please and thanks. :)