Answer:
C. 2,940 ft³
Explanation:
The building is composed of a triangular prism and a rectangular prism
Therefore,
Volume of air in the building = volume of the triangular prism + volume of the rectangular prism
Volume of triangular prism = ½*bhl
b = 4 yards = 4*3 = 12 ft
h = 15 - 9½ = 5½ = 5.5 ft
l = 20 ft
Volume of triangular prism = ½*12*5.5*20 = 660 ft³
Volume of rectangular prism = W*H*L
W = 4 yds = 12 ft
H = 9½ = 9.5
L = 20 ft
Volume of rectangular prism = 12*9.5*20 = 2,280 ft³
✔️Volume of air in the building = 660 + 2,280 = 2,940 ft³