The up and down rectangles have an area of 6 * 4 = 24 ft^2
There are 2 of them so area = 2*24 = 48.square feet.
There is 1 floor which has an area of 4*6 = 24 square feet
The area of one of hte triangles is 1/2 4 *3.46 = 6.92
Again, there are 2 of them so the total area for the triangles is 13.84
The total area is 48 + 24 + 13.84 = 85.84 square feet.