To find the surface area you will need to find the areas of all 6 surfaces. The 2 bases are trapezoids and the 4 lateral faces are rectangles.
This shape is a trapezoidal prism.
Trapezoid 1:
A = 1/2h(b1 + b2)
1/2 x 8(8 + 12)
A = 80 square inches
Trapezoid 2 = 80 square inches
Rectangle 1
A=bh
8 x 8= 64 square inches
Rectangle 2
A= 64 square inches
Rectangle 3
A = 8 x 9
A = 72 square inches
Rectangle 4
A = 12 x 8
A = 96 square inches
S.A.= 96+72+64+64+80+80
S.A.=456 square inches