If your looking for the volume of the figure, the answer is below:
l*w*h
8*4*8 = 256 cm^3
If your lookin for the surface area, the answer is shown below:
(8*4) * 4 = 128
(8*8) * 2 = 128
128 + 128 = 256
The answer for the volume is 256cm^3, and the surface area is 256 cm^ 2
(Note: When you write the answer, dont forget the cm^3 and cm^2 for each answer respectively. For volume it's cm^3, and for surface area it's cm^2. Thanks and have a great day:)