Imagine cutting out the tilted side of the cylinder such that the cylinder becomes vertical on that side, then sticking the piece that you previously cut out to the opposite side. This will form a vertical cylinder exactly.
Formula for volume of cylinder:
Base area × Height
= Area of circle × Height
= pie × radius^2 × Height
{Radius of circle, as indicated in the question, is 4, and height is 6}
= pie × (4)^2 × 6
= pie × 16 × 6
= pie × 96
= 96pie units^3 {Again, this question does not have units written down for each number, so write down the word "units" instead, and with a power of 3 since this is a volume.}
Hope this helps!