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 the fence. Also find the cost of the rope, if it costs $Rs.4$ per meter. $(Take\pi =3.14)$

Answer 1

The diameter of the garden is $21m$, then the radius will be $\frac{21}{2}m$.

The length of the rope used will be the circumference of the circular garden,

$length=2\pi r$

$=2\times \frac{22}{7}\times \frac{21}{2}$

$=66m$

As he makes 2 rounds of fence, then the length of the rope used is $2\times 66=132m$.

The cost of $1m$ rope is $Rs4$.

The cost of $132m$ is $Rs4\times 132=Rs528$.