Answer:
Since the 'base' and 'top' of any prism have the same shape, the surface area can be found by
surface area of prism = 2 * area of base + perimeter of base * H
So for the rectangular prism in your example..
surface area = 2LW + 2(L+W)H
= 2 * 7 * 4 + 2*(7+4)*5
= 56 + 2 * 11 * 5
= 56 +110
= 166 sq cm
Hope this helps
