(a) Here `a =(2)/(sqrt3)R`
`Now , (M)/(M') = ((4)/(3)prR^2)/(a^3)`
`=((4)/(3)piR^3)/((2)/(sqrt3)R)^3 = (sqrt3)/(2) pi, M' =(2M)/(sqrt3pi)`
Moment of inertia of the given axis,
`I = (M'a^2)/(6) = ((2M)/(sqrt3pi)xx((2)/(sqrt3)R))^2)/(6) = (4MR^2)/(9sqrt3pi)`
