> Maximal number of regions obtained by joining n points around a circle by straight lines. I was ready to attempt drawing that, but then I saw the other possi

> Maximal number of regions obtained by joining n points around a circle by straight lines. I was ready to attempt drawing that, but then I saw the other possible definition: > Also number of regions in 4-space formed by n-1 hyperplanes. So much easier to visualize it like this!