How to calculate volume of hollow column?

Given-

Height of column h = 5 m

Radius of column (R) = 900 mm = o.9 m

radius of column (r) = 600 mm = 0.6 m

Hollow column

Formula :

Volume  of hollow column = πR²h – πr²h

= πh (R² – r²)

= 3.14 x 5 ( 0.9² – 0.6²)

= 3.14 x 5 (0.81 – 0.36)

=3.14 x 5 x 0.45

=7.065 m³