Bottom face is 8*4=32
2 triangle's area is 4*3*1/2*2=12
5*8=40.
back face is 8*3=24
32+12+40+24=108
Thr front and back are composed of two right triangles with legs of 3 and 4
Their combined surface area = 3 * 4 = 12
The right side is a 3 x 8 rectangle = 24
The bottom is a 4 x 8 rectangle = 32
The top is a 5 x 8 rectangle = 40
Total surface area = 12 + 24 + 32 + 40 = 108 units^2