To find the volume of the given figure, we have to find the volumes of the 2 prisms that compose it.
For the rectangular prism, find the area of the base and then multiply it by the height:

For the triangular prism, find the area of the triangular base and then multiply it by the height:

Finally, find the sum of both volumes to find the volume of the figure:

It means that the volume of the figure is 135 m^3.