Answer to the home page question: (5π/3)*(3√2 - 4)
See Weisstein, Eric W. "Sphere-Sphere Intersection." From MathWorld--A Wolfram Web Resource.  This is the link.
The icons below link to some internal pages.

Interesting complex valued function : ${\sum }_{n=1}^{\infty }{\left(z}{n}\right)}^{n}$

Project Euler

Poker