This is not answering the question. You have found a volume (not that

of the pyramid as it happens), but the question asks for the lateral area,

which is the surface area of the solid less the area of the base.

The area of a single face is b*s/2, so the area of three of these is:

A = 3*b*s/2 = 3*3*6/2=27 sq inches.

where b is the lebgth of one of the base edges (they are all the same)

and s is the slant height.

RonL