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

Answer 1

d = diameter = 21 m

∴ radius of the circular garden

= \(\frac{d}{2} = \frac{21}{2}cms\)

circumference of the circular garden = 2πr

= 2 x \(\frac{22}{7}\times\frac{21}{2} = 66mts\)

Length of the rope needed to make one round of fence } = 66 mts

Length of the rope needed to make 2 rounds =
66 × 2 = 132 mts

cost of rope per metre = Rs. 4

Total cost of rope = 132 × 4 = Rs. 528