If you are trying to find the volume of this shape, then you use the equation V=B x W x H
So you would do:
V=B x W x H
V=2 x 3 x 2
Now, multiple this together. 2 x 3 is 6. Multiple 6 by 2, and you get 12.
The volume of your object is 12cm
Hope this helps :)
