Answer:
927 cubic inches
Step-by-step explanation:
The area of the octagonal base is ...
A = (1/2)Pa
where P is the perimeter, and 'a' is the apothem. Using the given numbers, the base area is ...
A = (1/2)(8·4)(4.83) = 77.28 . . . square inches
The volume of the prism is given by ...
V = Bh
where B represents the area of the base, and h is the height.
V = (77.28 in^2)(12 in) = 927.36 in^3
The volume of the prism is about 927 cubic inches.
