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 the fence. Also, find the cost of the rope, if it costs Rs. 4 per meter. $(Take\pi =\frac{22}{7})$

Answer 1

Diameter of the circular garden = 21 m
Therefore, radius of the circular garden = $\frac{21}{2}m$
Now, the circumference of circular garden = $2\times \pi \times r$
$=2\times \frac{22}{7}\times \frac{21}{2}$
$=22\times 3=66m$

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