The attachment consists of 2 exercises from my last week's homework that I attempted to prove using numerous strategies, but never found a good one.

I searched for a while for the characteristics of a cyclic quadrilateral to use for the set up of the first proof, but never got even that far, and thus didn't get very far at all (I know...No S*^%!). As for the second exercise, no axiom, theorem, definition, or combination seemed very strong to prove the part i proposition. That left part iii pretty hopeless.

Thanks!