Slide37.JPG

Slide38.JPG

  1. Chapter 11 Class 7 Perimeter and Area
  2. Serial order wise

Transcript

Ex 11.3, 12 The circumference of a circle is 31.4 cm. Find the radius and the area of the circle? (Take Ο€ = 3.14) Radius = r = ? Given, Circumference = 31.4 cm 2πœ‹r = 31.4 2 Γ— 3.14 Γ— r = 31.4 r = 31.4/(2 Γ— 3.14) r = 314/10 Γ— 100/(2 Γ— 314) r = 1/10 Γ— 100/(2 Γ— 1) r = 10/2 r = 5 cm Now, Area of circle = πœ‹r2 = 3.14 (5)2 = 3.14 Γ— 25 = 314/100 Γ— 25 = 314/4 = 157/2 = 78.5 cm2 ∴ Radius of circle is 5 cm & it’s area is 78.5 cm2

About the Author

Davneet Singh's photo - Teacher, Computer Engineer, Marketer
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.