Answer:
139
Step-by-step explanation:
First, find all the faces that you must find the areas of. In this case, you need to find the areas of two triangles and three rectangles.
In this triangular prism, the base is one triangle. If the area of the base is 7.75, we can assume that that holds true for both bases, and multiply 7.75 by 2 in order to find the area of both triangles.
Now find the area of each of the three rectangles by multiplying their individual heights and bases by each other. You should get 38, 47.5, and 38 as the areas of the rectangles.
Now add all the individual area's together. (They're bolded for clarity).