You can use GeoGebra to draw prisms and calculate the volume of those prisms.
GeoGebra Instruction 1
3D Graphics Algebra View and Graphics View under View in Menu. Graphics View. You can read more on how to draw a rectangle from GeoGebra Instruction 3 here. Graphics View and open 3D Graphics under View in Menu. Extrude to Prism, which you find by clicking on the ninth tool on the Toolbar (Pyramid) and select the fourth tool from that list. The prism is now drawn in 3D Graphics. The volume of the prism is shown in Algebra View.