The aim of this question was to find the bearing of S from T. Whenever you get that sort of question, always start measuring from the point which says "from" if you know what I mean :)
I've done the working out approximately so double check it.
Here is a list of the things you can do to revise for your GCSE maths:
use revision cards: One the best method out there to revise for maths. The idea is to write down examples, keywords, formulae etc... or anything you find hard to remember. When you are free like traveling on the bus, just get your cards out and start reading them.
revise with a partner : This is tricky one. Reason being you could potentially get distracted into a useless conversation or even worst get confused because the other person's understanding is lower than yours. My recommendation would be to team up with someone who is better than you :) on the subject concerned.
Make poster: This one is similar to making revision cards but on a bigger scale. The idea is to stick all the posters around your room so that they are sort of on your face all the time. Well when you are in your room or kitchen or........... wherever you fancy :). You will notice that those question you found difficult at first become quite easy once you see them again and again.
Talk out loud when revising: This a funny one as your parents or sibling might think that you've gone crazy. But here you going to read your notes or revision materials out loud. When you speak out loud, you tend to think more when you talk out loud rather than just reading things in your head. Try it :)
PAST EXAM PAPERS: Possibly the best one in my opinion. Actually this is a must. When you practice exam papers, first it gives you a feel of how exams questions are going to be like. Secondly, you can start noticing pattern on the sort of questions you are going to get. In maths, there's certain topic that always pop-up. Never miss this crucial part of your exam preparation. I often get asked by student where they can get hold of past exam papers. Well its' easy, all you need to do is enter your email and name on the form by the sidebar ==> and I will send out papers FREE OF CHARGE.