a square pyramid with base edge length 18 cm and height 12 cm
its volume
The formula for the volume of a pyramid is
... V = (1/3)Bh . . . . . where B is the area of the base and h is the height
The formula for the area of a square is
... A = s² . . . . . . . . . where s is the length of the side.
For the given pyramid, the area of the base is
... A = (18 cm)² = 324 cm²
so the volume is
... V = (1/3)(324 cm²)(12 cm) = 1296 cm³ . . . . . matches selection A