From the image shown, we can see the cube is built of ten smaller shapes. This means each individual cube is 1/10 the total volume. 80/10 = 8. This means w*l*h=8. Our possible options are 2*2*2 and 2*4*1. Since the shape's length, width, and height are clearly all different from the image, we know the latter must be the dimensions: 2*4*1.
