Check the picture below.
so, the triangular prism is really 2 triangles and 3 rectangles stacked up to each other at the edges. Let's simply get the area of each shape and sum them up, and that's the area of the prism.
![\bf \stackrel{\textit{two triangles}}{2\left[ \cfrac{1}{2}(\stackrel{base}{6})(\stackrel{height}{5.2}) \right]}+\stackrel{\textit{right-side rectangle}}{(8\cdot 6)}+\stackrel{\textit{left-side rectangle}}{(8\cdot 6)}+\stackrel{\textit{base rectangle}}{(8\cdot 6)} \\\\\\ 31.2+48+48+48\implies 175.2](https://tex.z-dn.net/?f=%5Cbf%20%5Cstackrel%7B%5Ctextit%7Btwo%20triangles%7D%7D%7B2%5Cleft%5B%20%5Ccfrac%7B1%7D%7B2%7D%28%5Cstackrel%7Bbase%7D%7B6%7D%29%28%5Cstackrel%7Bheight%7D%7B5.2%7D%29%20%5Cright%5D%7D%2B%5Cstackrel%7B%5Ctextit%7Bright-side%20rectangle%7D%7D%7B%288%5Ccdot%206%29%7D%2B%5Cstackrel%7B%5Ctextit%7Bleft-side%20rectangle%7D%7D%7B%288%5Ccdot%206%29%7D%2B%5Cstackrel%7B%5Ctextit%7Bbase%20rectangle%7D%7D%7B%288%5Ccdot%206%29%7D%20%5C%5C%5C%5C%5C%5C%2031.2%2B48%2B48%2B48%5Cimplies%20175.2)
445 + 210 + 525 = 1,180
500 + 85x = 1,180
-500 -500
85x = 680
/85 /85
x = 8
ANSWER
2(32-343x)
As calculated in the photo above