We have to calculate the suface of the four walls and the ceiling. Surface of the four walls=2(10 ft * 10ft ) + 2(12 ft * 10 ft)=200 ft² + 240 ft²= =440 ft² Surface of the ceiling=10 ft * 12 ft=120 ft²
Total surface=440 ft² + 120 ft²=560 ft²
Now, we have to caluclate the number of gallons of paint.