If you look at the figure, you can see there are two shapes; the rectangular prism (bottom) and triangular prism (top). First we find the volume of the rectangular prism by using the formula length x width x height. Put the values in which would be 12.5 x 3 x 4. You get 150cm^3. then for the triangular prism, the formula is V= base x length x height x 1/2. Put the values in, which would be 3 x 12.5 x 4 x 1/2. For that you get 75cm^3. Add both answers together and you get 225 cm^3.