ANSWER
36 cubic inches.
EXPLANATION
The volume of a square pyramid is calculated using the formula:
[tex]V = \frac{1}{3} {l}^{2} \times h[/tex]
where l² is the area of the base and h= 6 inches is the height of the square pyramid.
We substitute the values into the formula to get,
[tex]V = \frac{1}{3} \times 18 \times 6 \: {in}^{3} [/tex]
We simplify to get:
[tex]V = 6 \times 6 =3 6 {in}^{3} [/tex]
Therefore the volume of the square pyramid is 36 cubic inches.