(bash): The most useless commands (9)

After talking about

1. rev
2. yes
3. sl
4. cowsay
5. cmatrix
6. cal
7. rig

here another pretty useless command:

$ pi 10
3.141592653

Manpage:

DESCRIPTION
       The  pi  command  prints  100 decimal digits of Archimedes' constant pi or a number of
       digits specified by an integer parameter on the command line.