A gardener wants to fence a circular garden of diameter 21 m. 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 ₹4 per meter. ( Take π = 22/7)

Diameter of the circular garden = 21 m
∴ Radius of the circular garden = 21/2
Now Circumference of circular garden = 2πr = 2×22/7×21/2
= 22 x 3 = 66 m
The gardener makes 2 rounds of fence so the total length of the rope of fencing
= 2×2πr
= 2 x 66 = 132 m
Since, the cost of 1 meter rope = ₹ 4
Therefore, cost of 132 meter rope = 4 x 132 = ₹ 528

Class 7 Maths Chapter 11 Exercise 11.3

for more answers vist to:
https://www.tiwariacademy.com/ncert-solutions/class-7/maths/chapter-11/