Answer:
1,344 square inches
Explanation:
First, determine the faces that you have to find the areas of! In this situation, you need to find the areas of two trapezoids and four rectangles.
Finding the area of a trapezoid is pretty straightforward! Simply find the average of the two bases and multiply that by the height. ((5+15)/2)*12 should equal the area of one trapezoid. Because they're both the same trapezoid, you can multiply this area by two in order to get the area of both. This will get you 240.
Now, find the area of each of the rectangles by multiplying their individual bases and heights together. You'll find them to be 312, 360, 120, and 312.
Lastly, add all the areas together to get the total surface area.