We can think of the tent as the sum of two rectangles (both sides) and two triangles (front and back)
Each ofthe rectangles are 12ft lenght and 8.6ft height, so their area is:
Area of the rectangle = 12x8.6 = 103.2 square feet, since they are two, 103.2 x 2 = 206.4 square feet
Each of the triangles have a base of 10ft and a height of 7 ft, so their area is:
Area of the triangle = (10 x 7)/2 = 70/2 = 35, since they are also two, 35 x 2 = 70 square feet
Total area of the tent = 206.4 + 70 = 276.4 square feet
Answer:
276.4 square feet