Surface Area, Volume and Capacity (Cuboid, Cube and Cylinder) - ICSE Class 8 Maths Chapter 23

This chapter introduces the fundamental concepts of volume, capacity, and surface area for three-dimensional objects.

Full chapter content: https://plz.in/8maths23

Volume is defined as the space occupied by a solid body, while capacity refers to the internal volume of a container, or how much liquid or gas it can hold. The chapter focuses on three specific shapes: the cuboid, the cube, and the cylinder. For a cuboid (a rectangular solid), the volume is calculated by multiplying length, breadth, and height, and its total surface area is the sum of the areas of its six faces. A cube is a special type of cuboid where all edges are equal in length, making its volume the edge length cubed and its surface area six times the square of the edge.

Students will also learn how to apply these formulas to real-world problems involving rooms and boxes. For example, the lateral surface area of a room corresponds to the area of its four walls, which is essential for calculating painting or whitewashing costs. When dealing with boxes made of thick material, the chapter explains how to find the internal capacity by subtracting the wall thickness from the external dimensions. Additionally, a key principle taught is that when a solid object is melted and recast into a new shape, the volume of the material remains constant, allowing you to solve for missing dimensions of the new object.

The final section covers the cylinder, a solid with a uniform circular cross-section defined by its radius and height. The volume of a cylinder is found by multiplying the area of its circular base by its height, while the curved surface area represents the area of the vertical side around the cylinder. To find the total surface area, you must add the curved surface area to the area of the two circular ends. Throughout these calculations, the mathematical constant Pi is generally used as 22/7 unless a specific value is provided.

#dohrao #dohraoicseclassh8 #icseclass8 #icse #icseclass8maths #dohraoicseclass8maths