Just multiply all of them because Volume = Length x Width x Height. So it's 8.5 x 4.5 x 3.75. That equals 143.4375. Cubic inches is just there after you multiply, so you don't have to convert anything. So it's 143.4375 cubic inches.
This expression is already simplified.
I had that question yesterday
1-rotational
2-rotational
3-rotational
4-neither
(I’m like 99% sure)