volume of cone formula

CONES:

If one end of a line is rotated about a second fixed line while keeping the line's other end fixed, then a cone is formed.  The point about which the line is rotated is called the vertex and the base of the cone is a circle.

A cone is said to be right when the vertex is directly above the centre of the base.

Consider a cone in which base radius = r, height = h and slant height,

.

Then, we have

• Volume of the cone h cubic units

   

• Curved surface area of the cone sq units

   

• Total surface area of the cone 

   

= (curved surface area) + (area of the base)

sq units

SOLVED EXAMPLES

question The height of a cone is 24 cm and the diameter of its base is 14 cm. Find the slant height, volume, area of curved surface and the total surface area of the cone.

Solution:   Here, h = 24 cm and r = 7 cm.

Let the slant height be I cm. Then,

∴slant height = l cm = 25 cm.

Volume of the cone

Curved surface area of the cone

Total surface area of the cone =

= 704 cm2

CBSE NCERT Solutions for Class 8 Maths

class 8 maths NCERT solutions Chapter 1: Rational Numbers

class 8 maths NCERT solutions  Chapter 2: Linear Equations in One Variable

class 8 maths NCERT solutions  Chapter 3: Understanding Quadrilaterals

class 8 maths NCERT solutions Chapter 4: Practical Geometry

class 8 maths NCERT solutions  Chapter 5: Data Handling

class 8 maths NCERT solutions  Chapter 6: Square and Square Roots

class 8 maths NCERT solutions  Chapter 7: Cube and Cube Roots

class 8 maths NCERT solutions  Chapter 8: Comparing Quantities

NCERT Class 8 Maths solution Chapter 9: Algebraic Expressions and Identities

class 8 maths NCERT solutions  Chapter 10: Visualizing Solid Shapes

class 8 maths NCERT solutions Chapter 11: Mensuration

class 8 maths NCERT solutions  Chapter 12: Exponents and Powers

class 8 maths NCERT solutions  Chapter 13: Direct and Inverse Proportions

class 8 maths NCERT solutions  Chapter 14: Factorization

class 8 maths NCERT solutions  Chapter 15: Introduction to Graphs

class 8 maths NCERT solutions  Chapter 16: Playing with Numbers

Notes,worksheet and solved question for Maths class 8 

1.  class 8 maths notes on chapter Liner equation in one variable
2. class 8 maths notes on chapter algebric expression 
3. class 8 maths notes on chapter Mensuration 
4. class 8 maths notes on chapter Square and square roots 
5. class 8 maths notes on chapter statistice
6. class 8 maths notes on chapter practical Geometry
7. class 8 maths notes on chapter commericial maths
8. class 8 maths notes on chapter solid shape
9. class 8 maths notes on chapter quadrilaterals
10. class 8 maths notes on chapter exponents
11. class 8 maths notes on chapter factorisation 
12. class 8 maths notes on chapter inverse proporation 
13. class 8 maths notes on chapter cube and cube roots 

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