I think there are a couple things. First, my guess is that people whose strengths are more sequential than visual-spatial will find the geometry text more difficult than the algebra text (I think my kids are the opposite, though we shall see). Second, there's the proof-writing. While the other AoPS books include proof-ish problems for which reasoning needs to be explained (disclaimer: we haven't used all of those yet), geometry requires actual proofs, which I'd guess would be on the more difficult end of things for an 8 year old, though I suppose it depends on the kid.
I have a child taking the on-line geometry class right now. I love the weekly class problem sets - very challenging, more challenging than the book. At the moment, she's a little behind in her assignments - there have been a few problems that she hasn't figured out yet because she hasn't put in the time it will take. They are hard and I haven't figured them out yet either (again, an issue of time and effort and experience).
I don't see anything wrong with starting the geometry in parallel to the algebra, anticipating a pause if additional algebra is needed as mentioned by the PP, and then if it's too difficult, it could simply be put aside for later. There's no rush, after all; enjoy the banquet of math. I admit I am jealous of my child having the opportunity to learn geometry with AoPS - it's awesome.
Last edited by snowgirl; 10/22/14 09:02 AM.
