all you need to do is subtract. 133-87 which is 46 so <AKD is 46deg
Check the picture below.
notice the red rise/run slopes, are the same, thus those two lines are parallel, and also notice the green one for the other two lines, meaning both pair of lilnes are parallel.
106 because, 85 plus 21 = 106
I think it's just determining what the negative means. Negative with the x axis means to the left (because the left side is negative). Negative with the y axis is down (because the down side is negative.) So once you know that, it's obviously D because both are negative.
I hope that helped!
- mathwizzard3