Introduction
Chapter 21 introduces Mensuration II – Volumes and Surface Areas of a Cuboid and a Cube, one of the most practical and important topics in geometry. This chapter helps students measure space occupied by 3D objects and the surface areas required to cover them.
Key Topics Covered
This chapter teaches students to:
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Derive formulas for volume and surface area of cuboids and cubes
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Distinguish between lateral, total, and curved surface areas
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Solve real-life problems related to storage and packaging
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Apply unit conversions between cm³, m³, and liters
Each question in RD Sharma Class 8 is solved clearly with logical steps and real examples.
Formulas Explained
For a cuboid with length (l), breadth (b), and height (h):
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Volume = l × b × h
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Total Surface Area = 2(lb + bh + hl)
For a cube with side (a): -
Volume = a³
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Surface Area = 6a²
Understanding these formulas enables students to solve advanced mensuration questions with ease.
Applications in Real Life
These concepts are used in:
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Measuring storage boxes and tanks
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Calculating packaging materials
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Estimating volume of rooms and containers
Why RD Sharma Solutions are Beneficial
RD Sharma simplifies complex problems with examples and diagrams. Each exercise reinforces understanding of geometry through practical application and analytical reasoning.
Conclusion
Chapter 21 – Mensuration II (Volumes and Surface Areas of a Cuboid and a Cube) builds strong foundational skills in measurement and spatial visualization. Practicing RD Sharma solutions ensures complete conceptual mastery.