Answer:
L.A. = 384 cm²
S.A. = 640 cm²
Explanation:
We have four congruent triangles with base b = 16cm and height h = 12cm.
The formula of an area of a triangle:

Substitute:

The latearal area:

For the surface area we need the area of a base.
The base is a square with side a = 16cm.
The area of the base:

The surface area:
