In ICSE Class 9 Mathematics, the topic of mensuration covers various concepts related to the measurement of geometric figures. Here’s a summary of the key concepts typically included in this chapter:

1. **Area and Perimeter**:

– Formulas for finding the area and perimeter of basic shapes such as rectangles, squares, triangles, and circles.

– Understanding the difference between perimeter (the total length of the boundary) and area (the space enclosed by the boundary).

2. **Surface Area and Volume**:

– Formulas for finding the surface area and volume of basic 3D shapes such as cubes, cuboids, cylinders, cones, and spheres.

– Understanding the concept of surface area (the total area of all the surfaces of a 3D shape) and volume (the space occupied by a 3D shape).

3. **Composite Figures**:

– Calculating the area and perimeter of composite figures, which are made up of two or more simpler shapes.

– Applying the concept of breaking down complex shapes into simpler ones to calculate their area and perimeter.

4. **Applications of Mensuration**:

– Solving real-life problems involving area, perimeter, surface area, and volume.

– Examples include calculating the amount of paint needed to cover a wall, determining the cost of fencing a garden, or finding the volume of a container.

5. **Units of Measurement**:

– Understanding different units of measurement for length, area, and volume (e.g., centimeters, square meters, cubic centimeters).

6. **Practical Geometry**:

– Applying mensuration concepts in practical geometry, such as constructing shapes with given measurements or dimensions.

7. **Word Problems**:

– Solving word problems that require the application of mensuration formulas to find unknown quantities.

Overall, the mensuration chapter in ICSE Class 9 Mathematics focuses on developing students’ ability to calculate the measurements of various geometric figures and apply these concepts to solve real-world problems.