Check the picture below.
so, we have a hexagonal prism and a cube pegged to it.
the volume of the cube is simple, just a 3x3x3 = 27 in³.
the volume of the hexagonal prism, well we know the hexagonal bases are 23.4 in², and it has a height of 3 in, so the volume is simply that base times the height, or 23.4 in² * 3 in = 70.2 in³.
so the volume of the figure is simply both volumes added together, or namely 27 in³ + 70.2 in³ = 97.2 in³.
