1. To solve this exercise you must apply the formula for calculate the volume of a rectangular prism and the formula for calculate the volume of a rectangular pyramid:
2. Volume the rectangular prism:
V1=LxWxH
V1=(7 in)(3 in)(4 in)
V1=84 in³
3. Volume of the rectangular pyramid:
V2=BxH/3
B=(7 in)(3 in)=21 in
H=12 in-4 in=8 in
V2=(21 in)(8 in)/3
V2=56 in³
4. The volume of the composite figure is
V=V1+V2
V=140 in³