Whilst I do not mind posting this out of the thread made for Cambridge 3U, can you please
post the actual question next time to save us having to look for it. Some people might not even have the textbook.
Q9 was actually done in that thread I believe
http://community.boredofstudies.org...-3-unit-cambridge-question-answer-thread.html but you may need to look around for it.
Tips for Q10 since I'm not bothered to do it right now:
Triangle APB ||| Triangle TDA ||| Triangle TQC
Where T is the intersection of the lines DC and AE
Don't forget that we can manipulate right-angled triangles with angle sum of a triangle. Or use parallel lines. There's also vertically opposite angles to prove the latter similarities.
AQ = AT + TQ