Hello everybody, so I've just joined, thought maybe you guys could help me out since I've been banging my head against my desk for a few days now. http://imgur.com/4FVpan3 (incase the inline image doesn't work: http://imgur.com/4FVpan3) I'm stuck on problem 1.38. I know how to do it if the walls were orthogonal but since they aren't I'm stuck. I know how he's getting the 202 in the square root etc, but i have no idea where he's getting the 168cos(thetha) and subtracting it from. Can someone give me some tips about how to go about solving this problem? Thanks!