Answer:
128 m^3
Step-by-step explanation:
The volume of the rectangular prism base is (8 m)(8 m)(10 m), or 640 m^3.
The triangular 'cap' has a base area of 64 m^2 and a height of 6 m, and thus a volume of (1/3)(64 m^2)(6 m) = 128 m^3
