This is a 40 page Smartboard File explaining how to find the surface area of a triangular prism. The lesson starts with finding the area of a triangle. Next there is a breakdown of how you find the area of all 5 sides (basically the net). Next there is plenty of practice that includes a breakdown showing the area of the triangles, the area of the rectangles, and a final answer. This should help clear up any misunderstanding they might have.