Hey I wouldn't know for specialist mathematics; however, I can make a comment on methods through my encounters. From general observation is has become apparent that the following are required:
-Knowledge of similar triangles
-Geometry from Year 9 (this depends on what you're school taught you but generally if you did 'advanced math' all the geometry from then would be applicable I would say)
-I have come across questions which require your knowledge of the properties of a circle.
I don't know if all these are set in stone; however, mathematics is a bit different and to my knowledge VCAA could examine us on anything that we have learnt in our past years in maths. I wouldn't be completely sure but this is all I know so perhaps it is worth brushing up on middle-school geometry.