Answer:
Explanation:
Look at the area of a rectangle with length
and width
:

If we halve these: length
and width
:

So for all squares and rectangle the new area will be
of the original area.
So the overall surface area of the prism will be
of the original surface area (since it is just the sum of 4 rectangles and 2 squares).
An example is in the diagram. you can see how halving the dimensions causes the area to be quartered.