The base is a square with side length 0.6 ft, so the base area is 0.6*0.6 = 0.36 square feet.
Each lateral triangular panel has base 0.6 ft and height 7 ft. The area of one triangle is 0.5*base*height = 0.5*0.6*7 = 2.1 square feet
So four of these triangles combined give a lateral surface area of 4*2.1 = 8.4 square feet. Add this onto the base area to get 8.4+0.36 = 8.76 square feet of total surface area.
