Last updated at May 29, 2018 by Teachoo

Transcript

Ex 13.2, 4 The diameter of a roller is 84 cm and its length is 120 cm. It takes 500 complete revolutions to move once over to level a playground. Find the area of the playground in m2? [๐ด๐ ๐ ๐ข๐๐ ๐= 22/7] Roller is of form cylinder Radius = ๐ท๐๐๐๐๐ก๐๐/2 = 84/2 = 42 cm Area of roller = Curved surface of cylinder = 2ฯrh = (2ร22/7ร42ร120) cm2 = 31680 cm2 Area of 1 revolution = Area of roller = 31680 cm2 Area of 500 revolution = 500 ร 31680 cm2 Area of playground = 15840000 cm2 = 15840000 ร1/(100 ) ร1/(100 )m2 = 1584 m2

Example 2
Important

Ex 13.1, 6 Important

Ex 13.1, 7 Important

Ex 13.2, 3 Important

Ex 13.2, 4 Important You are here

Ex 13.2, 9 Important

Example 6 Important

Ex 13.3, 3 Important

Ex 13.3, 5 Important

Ex 13.4, 3 Important

Ex 13.4, 8 Important

Ex 13.4, 9 Important

Ex 13.5, 6 Important

Ex 13.5, 8 Important

Ex 13.5, 9 Important

Example 14 Important

Ex 13.6, 3 Important

Ex 13.6, 7 Important

Ex 13.7, 5 Important

Ex 13.7, 6 Important

Ex 13.7, 7 Important

Ex 13.7, 8 Important

Example 18 Important

Ex 13.8, 4 Important

Surface Area and Volume Formulas Important

Class 9

Important Questions for Exam - Class 9

- Chapter 1 Class 9 Number Systems
- Chapter 2 Class 9 Polynomials
- Chapter 3 Class 9 Coordinate Geometry
- Chapter 4 Class 9 Linear Equations in Two Variables
- Chapter 5 Class 9 Introduction to Euclid's Geometry
- Chapter 6 Class 9 Lines and Angles
- Chapter 7 Class 9 Triangles
- Chapter 8 Class 9 Quadrilaterals
- Chapter 9 Class 9 Areas of parallelograms and Triangles
- Chapter 10 Class 9 Circles
- Chapter 11 Class 9 Constructions
- Chapter 12 Class 9 Herons Formula
- Chapter 13 Class 9 Surface Areas and Volumes
- Chapter 14 Class 9 Statistics
- Chapter 15 Class 9 Probability

About the Author

Davneet Singh

Davneet Singh is a graduate from Indian Institute of Technology, Kanpur. He has been teaching from the past 8 years. He provides courses for Maths and Science at Teachoo. You can check his NCERT Solutions from Class 6 to 12.