Question

a rectangular solid has dimensions (a+2) by (a+4) by (3a). find it's volume

Answer 1

Volume of a rectangular solid = Length x breadth x height

=(a+2) x (a+4) x (3a)

=(a+2)(a+4)(3a)

$\begin{gathered} V=(a^2+4a+2a+8)(3a) \\ V=3a(a^2+6a+8) \\ V=(3a^3+18a^2+24)\text{ cubic unit} \end{gathered}$