1. A 120 ft tower is being held by three cables in tension. Cable AO is in 1000 lb of tension. Find the tension in the other cables and the vertical force from the tower if the whole system is at rest. 3. So using lots and lots of trig I was able to find most of the magnitudes, thetas, and phi's as you can see from the last 2 images. But now I'm lost from there. During office hrs. my prof. mentioned something about using unit vectors and then labeling the pts. A, B & C as coordinates A(-30,0,-20), b(-20,0,20), & c(40,0,10), but I don't see how those can help me. Any suggestions?