Cool Geometry

I found templates for this .. um... shape (it does have a long mathematical name) amongst the papers I've been sorting out, so I enlarged them on the photocopier and spent a happy evening in front of the TV, cutting, folding and glueing. It's now looking pretty good hanging in my office.

For Mother's Day last year, my daughters, who are chronically low on cash (I don't think that is such a bad thing when you're young, since it encourages you to be inventive) presented me with this:
... an origami model, made from numerous pieces of square paper, none of them cut and nothing glued, only folded and inserted into each other. I was so delighted!!