Question

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 Rs. $$4$$ per meter.(Take $$\pi =\dfrac{22}{7}$$)

Answer 1

Diameter of the circular garden$$=21$$m
$$\therefore$$ Radius of the circular garden$$=\dfrac{21}{2}$$m

Now, circumference of circular garden$$=2\pi r=2\times \dfrac{22}{7}\times\dfrac{21}{2}$$
$$=22\times 3=66$$m

The gardener makes $$2$$ rounds of fence so the total length of the rope of fencing $$=2\times 2\pi r=2\times 66=132$$m
Since the cost of $$1$$ meter rope$$=$$Rs. $$4$$
Therefore, cost of $$132$$ meter rope$$=4{\times}$$ $$132=$$Rs. $$528$$.