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 two rounds of fence. also find the cost of the rope , if it cost Rs.4 per meter. (Take π=22/7)​

Answer 1

Answer:

$\fbox \pink{diameter} = 21m \\ \\ \fbox \purple{radius} = \frac{21}{2}m \\ \\ \fbox \red{circumference} = 2\pi \: r \\ \\ 2 \times \frac{22}{7} \times \frac{21}{2} = \frac{22}{7} \times 21 \\ \\ 22 \times 3 = 66m \\ \\ \fbox \green{length \: of \: rope \: required} = 2 \times 66 = 132m \\ \\ \fbox \blue{cost} = 1m \: rope = 4 \\ \\ 132m \: rope = 4 \times 132 = 528$