I'm so confused, what do I need to know?
The textbook doesn't elaborate enough, or I'm I just losing it?
How many theorems do I need to know? Can I jus wing it? or do I need to memorise them?
you need to know theorem 4, 6, 9,14 and 19 (I think anyway, that's just from the top of my head). 1. angles in a triangle add to 180 degrees 2.exterior angles of a triangle are equal to the sum of the opposite angles 3. sides ad angles of a parallelogram are equal 4. the angle at the centre of a circle is twice any other angle on the same arc and 5. Pythagoras's theorem. you definitely cannot wing it you'll have to memorise them. I did it by just writing it out loads of times. there are videos on youtube and on various other websites that explain them better.
Here is a website, scroll down and you will see five proofs HL only, you have to learn five of them.