Surface Areas And Volumes Class 9th Notes - Free NCERT Class 9 Maths Chapter 13 Notes - Download PDF

Surface Areas And Volumes Class 9th Notes:

The complete surface area and volume formulas for various three-dimensional shapes are discussed in NCERT Class 9 Math Chapter 13 Notes, along with a detailed explanation. The surface area of any three-dimensional object can be divided into three categories: Curved Surface Area (CSA), Lateral Surface Area (LSA), and Total Surface Area (TSA). CBSE class 9 Math chapter 13 notes will offer students an overview of all the significant and relevant sections as well as highlight the significant references from the CBSE revision notes. The latest NCERT Syllabus and CBSE regulations were used to build, notes for class 9 Math chapter 13. For more information on any of the topics presented in this chapter, students can refer to the following resources.

Also, students can refer,

• NCERT Class 9 Maths Notes
• NCERT Solutions for Class 9 Maths Chapter 13 Surface Areas And Volumes
• NCERT Exemplar Class 9 Maths Chapter 13 Solutions Surface Areas And Volumes

NCERT Class 9 Math Chapter 13 Notes: Topic 1

Area, Surface, And Volume

The quantity of space inside a 2D object's boundary is referred to as its area. The overall area occupied by a surface of a solid 3D object is measured by its surface area. It is measured in m2, cm2 etc. The quantity of 3D space encompassed by a closed border is referred to as volume. It is measured in m3, cm3, litre etc. It is commonly used to calculate the amount of liquid, air, grains, and other materials in a three-dimensional container.

NCERT Class 9 Math Chapter 13 Notes: Topic 2

Cuboid

A cuboid is a figure that is surrounded by six rectangular surfaces. A cuboid's opposite surface is equal and parallel. There are 12 edges and 8 corners on a cuboid. The vertex of a cuboid is each of its four corners. The diagonal of a cuboid is the line segment connecting the opposite vertices. In a cuboid, there are four diagonals.

Volume of cuboid = Length × Breadth × Height = lbh
Lateral surface area = 2 (Length + Breadth) × Height = 2 (l + b) h
Total surface area = 2 (Length × Breadth + Breadth × Height + Height × Length) = 2 (lb+bh+hl)
Total length of cuboid = 4 (l + b + h)

Diagonal of cuboid = √ [(l)²+(b)²+(h)²]

NCERT Class 9 Math Chapter 13 Notes: Topic 3

Cube

A cube is a cuboid with the same length, width, and height. Six surfaces, twelve edges, eight corners, and four diagonals make up a cube.

Volume of cube= (lenghth of side)³ = l³
Lateral surface area = 4 × (lenghth of side)² = 4 l²
Total surface area = 6 × (lenghth of side)² = 6 l²
Total length of cube = 12 l
Diagonal of cube = √3 l

NCERT Class 9 Math Chapter 13 Notes: Topic 4

Right Circular Cylinder

A solid generated by the revolution of a rectangle around one of its sides is known as a right circular cylinder.

The volume of a cylinder = πr²h
Curved surface area or lateral surface area = 2πrh
Total surface area = Curved surface + 2 × Base area = 2πrh + 2πr² = 2πr(h+r)

NCERT Class 9 Math Chapter 13 Notes: Topic 5

Cone

A right circular cone is a solid formed when a triangle is rotated around one of its sides (other than hypotenuse).

Volume of cone = (1/3)πr²h

Curved surface area or lateral surface area = πrl

Total surface area = Curved surface area + Base area

= πrl + πr²

=πr(l+r)

l = √ (h²+r²)

h = √ (l²-r²)

r = √ (l²-h²)

NCERT Class 9 Math Chapter 13 Notes: Topic 6

Sphere

A solid encircled by a curving surface whose points are all the same distance apart from a fixed point. The fixed point is known as the sphere's centre. The radius of the sphere is the line segment connecting the sphere's centre to any point on the surface.

Volume of the sphere = (4/3)πr³

Surface area of the sphere = 4πr²

NCERT Class 9 Math Chapter 13 Notes: Topic 7

Hemisphere

A plane that passes through the centre of a sphere divides it into two equal halves. Each component is referred to as a hemisphere.

Volume of hemisphere = (2/3)πr³
The curved surface area of hemisphere = 2πr²
Total surface area of hemisphere = 2πr² + πr² = 3πr²

Significance of NCERT Class 9 Math Chapter 13 Notes

Surface area and volumes class 9 notes are based on the current CBSE syllabus and provide an outline of the class 9 chapter Surface area and volumes. The purpose of CBSE class 9 Math chapter 13 notes is to help students learn and revise more easily. Students will learn about the surface areas and volumes of various forms such as the cuboid, cube, right circular cylinder, right circular cone, and sphere through NCERT notes for class 9 chapter. class 9 Surface Areas and Volumes notes present the most important notes and formulas for each of the shapes in a simple manner. of NCERT Class 9 Math Chapter 13 Notes help students to recollect the points easily and crack good scores in exams. Students can download Surface Areas and Volumes class 11 pdf download and study offline.

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• NCERT solutions for class 9 Maths
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• NCERT Exemplar Class 9 Maths solutions
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