Let’s solve each problem one by one. We’re finding the
volume of each 3D shape. Volume tells us how much space is inside the shape — like how much water it could hold if it were a container.
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Problem 1: Cube
This is a cube — all sides are equal.
Each side = 5 cm.
Volume of a cube = side × side × side
= 5 × 5 × 5
= 25 × 5
=
125 cm³
✔ Check: 5×5=25, 25×5=125 → correct.
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Problem 2: Rectangular Prism (Box)
This is a box with:
- Length = 11 cm
- Width = 6 cm
- Height = 6 cm
Volume = length × width × height
= 11 × 6 × 6
First, 6 × 6 = 36
Then, 11 × 36
Break it down:
10 × 36 = 360
1 × 36 = 36
Total = 360 + 36 =
396 cm³
✔ Check: 11×6=66, 66×6=396 → correct.
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Problem 3: Triangular Prism
This shape has a triangle as its base and extends into a prism.
We need to find:
- Area of the triangular base
- Then multiply by the length (or depth) of the prism
The triangle has:
- Base = 8 cm
- Height = 5 cm (the perpendicular height from base to top point)
Area of triangle = (base × height) ÷ 2
= (8 × 5) ÷ 2
= 40 ÷ 2
=
20 cm²
Now, the prism goes back 12 cm (this is the “length” or “depth” of the prism).
Volume = area of base × length
= 20 × 12
=
240 cm³
✔ Check: 20×12 = 240 → correct.
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Final Answer:
1) 125 cm³
2) 396 cm³
3) 240 cm³
Parent Tip: Review the logic above to help your child master the concept of finding surface area worksheet.