The formula of the volume of a square pyramid is:
Volume = a^2 (h/3)
432 = 12^2 (h/3)
432 = 48h
h = 9 ft.
But we need to find the slant height.
The slant height forms the hypotenuse of the vertical height and half the base.
slant height = square root (height^2 + base^2)
sh = square root (9^2 + 6^2)
sh = square root (117)
sh = 10.82 ft
So the slant height is equal to 10.82 feet.