The volume of a figure is equal to its length multiplied by its width multiplied by its height.
Volume = 3 x 6 1/4 x 14
Volume = 42 x 6 1/4
Volume = (42 x 6) + (42 x 1/4)
Volume = 252 + 10 1/2
Volume = 262 1/2 ft^3
Answer: 262 1/2 ft^3
Hope this helps!