Just doing this for points

So, what you are supposed to find here is the surface area of this rectangular prism. So the answer is 52 units of the special reflective material is needed.

Since total surface area of a rectangular prism = 2(lb + bh + hl)

Where l = length of the ice block

b = width of the ice block

h = height of the ice block

Now total surface area for the given dimensions = 2(4×2 + 2×3 + 3×4)

= 2(8 + 6 + 12)