They are a set of templates. I think the inventor has several you tube videos. lemme look...
http://www.youtube.com/watch?v=R2gRzT_5sFM
here is a quick video about them. You can do a search for Angle Play or for Margaret Miller to find out more
I dunno, maybe the owner would let me do a little teaching session on here?
And. lol.. I do NOT have any stock in Angle Play, they are just one of my favorite tools to make cool looking blocks!