Question

execise 11.3 of class 7 ncert questions is no.4​

Answer 1

Question:

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 costs of the  rope, if it cost Rs 4 per meter. (Take π =  22/7 )

Answer with explanation:

Diameter = 21m

Then, radius = 21/2 m

Circumference = 2πr = 2(22/7)(21/2)

                                   = 3(22)         [Cancellation of 7 &21, 2 & 2]

                                   = 66

2 rounds = 2(66) = 132 m

Cost for 1 meter = Rs. 4

Cost for 132 meters = 4(132)

                                 = Rs. 528

Hope it helps!!