Looking at the figure, there seems to be a chunk missing from the front. Since the overall length is 15 inches, and the length near the missing chunk is 12, then the missing length is 3. If that chunk was filled in, this would have been a 17 * 15 * 8 rectangluar prism. That would have been 2040 cubic inches. (120 * 17) However, a 3 by 8 by 3 triangular prism is missing.
