Answer:
340 ft^2
Step-by-step explanation:
The uppermost triangle has base 10 ft and height 12 ft. Thus its area is A = (1/2)(10 ft)(12 ft) = 60 ft^2. There are four such triangular areas, so their total area is 4(60 ft^2) = 240 ft^2. The base is 10 ft by 10 ft, which comes out to 100 ft^2.
Thus the total surface area is 240 ft^2 + 100 ft^2, or 340 ft^2
