How to calculate volume of ccp, fcp and hcp unit cells?

@ ayman 
actually the volume means the  (side ) ^ 3 
so, as far as fcc is concerned then 
a= 2 root 2 r 
so, a cube = (2 root 2 r ) ^ 3 – volume of fcc 
as far as bcc is concerned then . 
a = 3 / root 2 r 
so a cube =  (3/ root 2 r ) ^ 3 – volume of bcc . 
and these ccp are under the catagory of fcc . 
anathor oneis simple cubic 
for that 
a = 2 r 
in which a is one side . 
and r is the radii 
HOPE ITCLEARS YOUR DOUBT 
ALL THEBEST ..