Zero cubic yards of dirt--you just removed it. There are 6 cubic yards of air now filling it, and the 6 cubic yards of dirt is more than likely in a neat little mound right next to the hole.
If you want your answer in cubic feet, you have (2x3ft wide) times (3x3ft long) times (1x3ft deep)= 6x9x3=162 cubic feet. You just multiply these and gor=t your answer.
