Answer:
348in²
Explanation:
6*8 = 48. This is the surface area of the largest rectangle.
6*9 = 54. This is the surface area of the top rectangle.
8*9 = 72. This is the surface area of the smallest rectangle.
The total is 72+54+48, so 174.
Because there are two of each rectangle, you times this number by 2.
174 * 2 = 348in².