so hmm notice the picture below
what you really have is, 2 pentagons and 5 rectangles, stacked up to each other at the edges
so.. .the surface area of the figure, will be, the area of those 5 rectangles added together plus the area of those 2 pentagons
now... notice, each rectangle is a 12x8
now.. to get the pentagons area, keep in mind, the area of a regular polygon is 1/2 * apothem * perimeter
you have the apothem, is given, one side is 12 units long, the perimeter is all sides added together, thus 12+12+12+12+12
so.. get the area of each of the rectangles and those pentagons, sum them up, and that's the surface area of the figure