How would you find the length of RS? What do you have to find first? Can someone please explain this to me step by step? Help is appreciated!

http://img355.imageshack.us/img355/7590/pg3367ut0.jpg

Same for this one, how would you find the length of TU? Where would you start and what do you have to do?

http://img247.imageshack.us/img247/7826/pg3368qt4.jpg