1/3*(81*sqrt(3)/4)*sqrt3(6)
\(\frac{1}{3}\times(\frac{81\times\sqrt3}{4})\times\sqrt3\times6\)
= \(6\times\frac{1}{3}\times(\frac{81\times\sqrt3\times\sqrt3}{4})\)
=\(2\times\frac{243}{4}\)
=\(\frac{243}{2}\)
