31
Oct
Class 9 - Surface areas and Volumes, Math - Class 9 | NCERTClass 9 math tutorials, cube, cuboid, math, mathemafia, mathematics, NCERT, surface area, surface area of cube and cuboid
Question 1: A plastic box 1.5 m long, 1.25 m wide and 65 cm deep is to be made. It is opened at the top. Ignoring the thickness of the plastic sheet, determine:
(i) The area of the sheet required for making the box.
(ii) The cost of sheet for it, if a sheet measuring 1m2 costs Rs. 20.
Prerequisite
Finding surface area of a cube or a cuboid is quite simple. Every cube/cuboid has 6 sides. All we need is find the area of all six sides and add – this will be the total surface area of the cube/cuboid.
A cube is a cuboid that has all edges of equal length. Hence, every cube is a cuboid as well but every cuboid is not a cube.
It is recommended to understand the core concept of area, surface area and volume before we attempt any question based on these concepts.
Derivation of formula – Surface area of cube and cuboid
Chapter 13 – Surface areas and Volumes
Concepts
- Area / Surface area / Volume – Introduction
- Surface Area of Cube and Cuboid
- Volume Of Cuboid and Cube
- Surface Area of Right Circular Cylinder
- Volume and capacity of Cylinder
- Right circular Cone
- Surface Area of Right circular Cone
- Volume of Cylinder vs Cone
- Litres and Cubic centimetre (cm³)
- Cubic meters to litres