Explanation:
do I see this correctly ? this is not a pyramid but a triangular prism ?
the following bases on this assumption.
the surface area consists of 5 parts :
front and back triangles (2)
left and right rectangles (2)
bottom rectangle (1)
the area of a rectangle is
length × width
the area of a triangle is
baseline × height / 2
so, in our case we have
front and back triangles : 10×12/2 × 2 = 120 in²
left and right rectangles : 2×13 × 2 = 52 in²
bottom rectangle : 10×2 = 20 in²
so, the total surface area is
120 + 52 + 20 = 192 in²