Ex 9.2, 12 - Chapter 9 Class 7 Perimeter and Area

Last updated at Dec. 16, 2024 by

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Ex 9.2, 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 = (πŸ‘πŸ.πŸ’)/(𝟐 Γ— πŸ‘.πŸπŸ’) 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 = πŸ‘πŸπŸ’/𝟏𝟎𝟎 Γ— 25 = 314/4 = 157/2 = 78.5 cm2 ∴ Radius of circle is 5 cm & it’s area is 78.5 cm2

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Davneet Singh

Davneet Singh has done his B.Tech from Indian Institute of Technology, Kanpur. He has been teaching from the past 14 years. He provides courses for Maths, Science and Computer Science at Teachoo