First, lets find the area of the base of the prism:
In this case, the area is:

Then, we can find the area of the side that has the shape of a right triangle:
The area of this triangle is:

finally, the remainin face of the prism is a rectangle with the following measures:
Then the area of this rectangle is:

Now, notice that the prism has two faces in the shape of the right triangle and two faces in the shape of a rectangle, then, the total area surface will be:

therefore, the surface area is 1340in^2