software to learn algebra and geometry

[bakin]

My dad is a philosophy major at school, and feels that he would do a lot better with the logic if he understood math a little better. Can anybody here recommend a good software for learning algebra and geometry? I asked him about using books, but he wants to be able to have feedback with what he did wrong. Any suggestions?

Thanks!

[jkerrigan]

http://www.bagatrix.com/

[rochfor1]

I know some people that swear by Geogebra (http://www.geogebra.org) for illustrating geometry to their students.