# Ex 11.3, 4 - Chapter 11 Class 7 Perimeter and Area

Last updated at Dec. 12, 2018 by Teachoo

Last updated at Dec. 12, 2018 by Teachoo

Transcript

Ex 11.3, 4 A gardener wants to fence a circular garden of diameter 21m. Find the length of the rope he needs to purchase, if he makes 2 rounds of fence. Also find the cost of the rope, if it costs Rs 4 per meter. (๐๐๐๐ ๐=22/7) Since the gardener makes two rounds of the fence Thus, Length of rope required = 2 ร Circumference of circular garden Diameter = 21 m Radius = r = ๐ท๐๐๐๐๐ก๐๐/2 = 21/2 m Circumference of circular garden = 2๐r = 2 ร 22/7 ร 21/2 = 22/7 ร 21 = 22 ร 3 = 66 m Now, Length of rope required = 2 ร Circumference of circular garden = 2 ร 66 = 132 m Now, we also need to find cost of rope, Given, Cost of 1 m rope = Rs 4 Cost of 132 m rope = Rs 4 ร 132 = Rs 528 โด It would cost Rs 528 to fence the garden

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Davneet Singh

Davneet Singh is a graduate from Indian Institute of Technology, Kanpur. He has been teaching from the past 9 years. He provides courses for Maths and Science at Teachoo.