Answer:
3660ft^3
Step-by-step explanation:
4ft x 30ft x 15ft = 1800ft^3
(12ft - 4ft)(30ft - 7ft - 8ft)(15ft) / 2 = 900ft^3
(12ft - 4ft) x 8ft x 15ft = 960ft^3
1800ft^3 + 900ft^3 + 960ft^3 = 3660ft^3
