Given:
A combined figure of a triangular prism and a cuboid.
To find:
The volume of the finished object assuming it is empty inside.
Solution:
From the given figure it is clear that the dimensions of the cuboid are 6 cm, 8 cm and 5 cm.
So, the volume of the cuboid is:
The volume of the cuboid is 240 cubic cm.
The area of a triangle is:

Thus, the base area of the triangular prism whose base is 8 cm and height 4 cm, is:


The volume of a triangular prism is:

Where, B is the base area and h is the height of the prism.
The base area of the triangular prism is 16 square cm and the height is 5 cm. So, the volume of a triangular prism is:


Now, the volume of the given figure is:



Hence, the volume of the finished object is 320 cubic cm.