Hypersphere in 4 dimensions, I am having problem with finding the surface area of it. please help.
I know that surface area will have 3 dimensions in 4 dimensional space, I am having trouble to evaluate it
Circumference of circle= $2\pi r$
Surface area of sphere = $4\pi r^2$
Now, Surface area (or whatever, it will be having dimensions of a volume) of hypersphere = ??