The volume of a pyramid is given by:
V=1/3×(base area)×height
suppose the base of the pyramid is square:
volume=225 cubic units'
height=3 units
thus plugging in our values in the formula
225=1/3×(base area)×3
thus
base area=225
hence we conclude that if the base is square then the dimensions will be:
L=√225=15 units
thus the answer is 15 units by 15 units base