\(Vol_{p}= L ~ x ~ W ~ H\)

\(Vol = Vol_{outside} - Vol_{inside}\)

\(Vol_{outside}= 40x80x12 \)

\(Vol_{outside}= 38400 ~ ft^3 \)

To calculate the volume of the inside rectangular parallelepiped, solve first the dimensions.

The length is \(80-4 = 76 ~ft\) and the width is \(40-4 = 36 ~ft\)

\(Vol_{inside}= 36x76x12 \)

\(Vol_{inside}= 32832 ~ft^3 \)

\(Vol = 38400 - 32832\)

\(Vol = 5568 ~ft^3\)

\(Vol = \frac{5568}{27} ~yd^3\), \(1 yd^3 = 27 ft^3\)

\(Vol = 206.22 ~yd^3\)