My mother's boyfriend's son who is in 6th grade asked me a question about the math they are learning. I thought it wouldn't be too bad but I cannot for the life of me figure it out. A solution would be greatly appreciated. 1. The problem statement, all variables and given/known data https://postimg.org/image/1tsa4v4t8r/ 2. Relevant equations https://www.mathsaccelerator.com/geometry/angle-rules 3. The attempt at a solution I tried my best but my best wasn't good enough.