1. The problem statement, all variables and given/known data I'm sure this is quite simple, but I don't understand the notation. This is from a supplemental book that we have to do outside of class--there isn't a matching textbook and I really don't understand what they want here. 2. Relevant equations I noticed that if i square, sum, squareroot the left sides of the equations i get the right, so i am thinking that is a hypotenuse. So pythagorean theorem probably applies somewhere. But maybe not. 3. The attempt at a solution I'm sorry, but I don't know what to put here. I know it looks like I'm being super lazy but I have already wasted way too much time trying to figure this out by reading and re-reading in my textbook. It's just not there. I really am not asking for someone to do my work, but if you could please give a clue as to what one of the equations may sound like read out loud it would help immensely in this search. I just found out our professor would like for us to turn in this 320 page workbook by the end of the semester. It wasn't on the syllabus so I didn't know. Since we had to buy six books I really didn't realize we were supposed to be doing all of this one, too. I only have about 100 pages of it done so far and we only have a couple of weeks left of class. Thank you.