NCERT Solutions for Class 8 Maths Chapter 9 Mensuration - Free PDF Download
FAQs on NCERT Solutions for Class 8 Maths Chapter 9 Mensuration
1. What is the stepwise method to solve questions in NCERT Solutions for Class 8 Maths Chapter 9 Mensuration as per CBSE 2025–26 guidelines?
To solve Chapter 9 Mensuration questions:
- Read the question carefully and note all given values (dimensions, units).
- Identify the shape (e.g., rectangle, trapezium, cuboid, cylinder).
- Select the correct formula for area, perimeter, surface area, or volume as required.
- Substitute given values into the formula. Ensure units are consistent.
- Show all calculation steps clearly as per CBSE marking scheme.
- Write your final answer with correct unit (cm, m, cm2, m3 etc.).
2. How do you determine which formula to use for area or volume in Mensuration problems in NCERT Class 8 Maths Chapter 9?
Identify the geometrical shape involved by analyzing the problem (e.g., if the problem mentions parallel sides and height, it may be a trapezium). Refer to the standard formula table for Mensuration:
- For area of rectangles: Area = length × breadth
- For area of trapezium: Area = ½ × (sum of parallel sides) × height
- For volume of cuboid: Volume = length × breadth × height
- For surface area of cylinder: Surface area = 2πr(r + h)
3. What are the most common mistakes students make while solving Mensuration questions in Class 8 NCERT Solutions?
Common mistakes include:
- Mixing different units without conversion (e.g., cm and m together).
- Using incorrect formulas or misidentifying the shape.
- Missing out steps in calculations (leading to loss of marks per CBSE scheme).
- Not writing the final answer with the correct unit.
- Forgetting to add areas or perimeters of separate parts when the figure is composite.
4. How do you approach questions involving composite figures in Mensuration for Class 8 NCERT Solutions Chapter 9?
For composite figures:
- Break the figure into known shapes (triangles, rectangles, trapeziums, etc.).
- Calculate area or perimeter for each part separately using respective formulas.
- Add or subtract areas/perimeters as needed, based on how the figures are combined or cut out.
- Summarize the calculation and present a clear final answer with units.
5. Why do we use nets to find surface areas of solid shapes in NCERT Solutions for Class 8 Maths Chapter 9 Mensuration?
Nets visually ‘unfold’ a 3D solid into 2D faces, so you can measure or calculate the area of each face. Adding the areas of all faces gives the total surface area. This technique helps avoid missing any surface and is especially useful for solids like cuboids, cubes, and cylinders as taught in the Class 8 Mensuration syllabus.
6. How can understanding Mensuration concepts help solve real-life problems, according to NCERT Solutions for Class 8 Maths?
Mensuration concepts are applied to measure land, calculate costs for tiling or painting, estimate volumes of containers (like tanks), and determine the area for fencing or carpeting. Mastery enables students to handle practical situations involving shapes, areas, and volumes efficiently.
7. What is the correct process to convert between different metric units in Mensuration problems in Class 8 Maths?
Use standard metric conversions:
- 1 m = 100 cm; 1 cm = 10 mm
- Area: 1 m2 = 10,000 cm2
- Volume: 1 m3 = 1,000,000 cm3; 1 L = 1,000 cm3
8. What should you do if you are given an area or volume and asked to find an unknown dimension in NCERT Class 8 Maths Chapter 9 Mensuration?
Rearrange the standard formula to solve for the unknown dimension. For example, if Volume = length × breadth × height and you are given the volume and the other two dimensions, use:
Height = Volume ÷ (length × breadth)
Plug in the known values and calculate the unknown. Always state the unit in your final answer.
9. How are the formulas for surface area and volume of a cylinder different as per NCERT Solutions for Class 8 Maths Chapter 9?
- Surface area of a cylinder: 2πr(r + h) (includes both curved and base areas, measured in square units)
- Volume of a cylinder: πr2h (measures the space inside, in cubic units)
10. How can you identify whether a Mensuration problem is about 2-dimensional or 3-dimensional figures in Class 8 Maths Chapter 9?
If the problem involves measurements like length and breadth (no height/depth), deals with area or perimeter, it's 2D (e.g., rectangle, trapezium). If it involves height, surface area, or volume, and describes objects occupying space (e.g., cube, cuboid, cylinder), it's 3D.
11. What is the difference between lateral/curved surface area and total surface area in solid shapes for Class 8 Mensuration?
Lateral or curved surface area refers to only the side/surface excluding the top and bottom (e.g., curved area of a cylinder). Total surface area includes all faces, i.e., for a cylinder: both bases and the curved surface. For full coverage, always use total surface area unless the question specifies otherwise.
12. In NCERT Solution for Class 8 Maths Chapter 9, how is the area of a general quadrilateral calculated when two perpendiculars are dropped to the diagonal?
Area = ½ × diagonal × (sum of perpendiculars from the other two vertices). This formula works when the diagonal divides the quadrilateral into two triangles. Apply the correct values for the diagonal length and the two heights for an accurate result.
13. What strategies help secure full marks in Mensuration solutions according to CBSE's latest pattern for Class 8?
- Show all calculation steps in sequence, not just the final answer.
- Write the correct units at each stage.
- Double-check conversions and formula application.
- Ensure diagrams (if asked) are labeled and neat.
- State the reason/step for each formula used (as per CBSE step marking).
14. What is a common misconception students have about the perimeter versus area in Mensuration problems (Class 8 NCERT Solutions)?
Many students confuse area and perimeter: perimeter is the total length around a 2D shape measured in linear units (cm, m), while area is the space inside, measured in square units (cm2, m2). Always match formula and units to the question’s requirement.
15. How does solving all NCERT Solutions for Class 8 Maths Chapter 9 Mensuration improve overall mathematical skills?
It strengthens calculation accuracy, unit awareness, logical application of formulas, and boosts conceptual clarity—key for advanced topics in later classes and for real-world problem-solving in daily life. Consistent NCERT practice ensures confident exam performance.

















