Difficulties with Core Graphics framework


I’ve just read this chapter. I tried to do the challenges but I just could finish one of them, the rest was very hard for me.
While I was reading the chapter(and the book) I’ve never had problem and I understood everything,(I sometimes research some fail, but no problem) but when I have reached the part of core graphics I’d got lost and I don’t know if either this framework is difficult or I have to reread this part(I dont know if it will be important this part later).

What do you think guys?


Vector graphics are a difficult concept and these challenges are pretty hard.