To find the
total volume of composite rectangular prisms, we break each figure into separate rectangular prisms (boxes), calculate the volume of each using the formula:
>
Volume = Length × Width × Height
Then, we
add the volumes together.
---
a.
This figure is made of
two identical rectangular prisms stacked vertically.
Each prism has:
- Length = 14 cm
- Width = 3 cm
- Height = 5 cm
Volume of one prism = 14 × 3 × 5 =
210 cm³
Since there are two, total volume = 210 × 2 =
420 cm³
✔ Answer: V = 420 cm³
---
b.
This is a step-like figure. We can split it into
two rectangular prisms:
#### Bottom prism:
- Length = 15 in
- Width = 4 in
- Height = 6 in
→ Volume = 15 × 4 × 6 =
360 in³
#### Top prism (on the right):
- Length = 7 in
- Width = 4 in (same as bottom)
- Height = 3 in
→ Volume = 7 × 4 × 3 =
84 in³
Total volume = 360 + 84 =
444 in³
✔ Answer: V = 444 in³
---
c.
This is an L-shaped figure. Split into two prisms:
#### Bottom prism (longer part):
- Length = 10 cm
- Width = 3 cm
- Height = 2 cm
→ Volume = 10 × 3 × 2 =
60 cm³
#### Top prism (on the left):
- Length = 6 cm (only the left part sticks up)
- Width = 3 cm
- Height = 4 cm
→ Volume = 6 × 3 × 4 =
72 cm³
Total volume = 60 + 72 =
132 cm³
✔ Answer: V = 132 cm³
---
d.
This is another step-like figure. Split into two prisms:
#### Bottom prism:
- Length = 10 m
- Width = 3 m
- Height = 6 m
→ Volume = 10 × 3 × 6 =
180 m³
#### Top prism (on the left):
- Length = 8 m
- Width = 3 m
- Height = 12 – 6 =
6 m (since total height is 12m, and bottom is 6m)
→ Volume = 8 × 3 × 6 =
144 m³
Total volume = 180 + 144 =
324 m³
✔ Answer: V = 324 m³
---
##
✔ Final Answers:
a. V =
420 cm³
b. V =
444 in³
c. V =
132 cm³
d. V =
324 m³
---
Let me know if you’d like a diagram or visual breakdown for any of these!
Parent Tip: Review the logic above to help your child master the concept of volume of cube and rectangular prism worksheet.