It is well known the formula to calculate the volume of a pyramid: $V=\frac {1} {3} bh$, where where $b$ is the area of the base and $h$ the height from the base to the apex.
However I need to compare calculating of the volume via triple integral as well and make sure the results are the same.
The pyramid is bounded by planes: $x=0$, $y=0$, $z=0$ and the plane $\alpha$: $9x-y-3z=54$. So, I need to find $b$ and $h$ to calculate the volume via the formula. Then to calculate the triple integral with no clear boundaries?