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 $\pi$ = $\frac{22}{7}$ )

Answer 1

$d=21 \;m$

$r=\frac{21}{2}$

Circumference = $2\pi r$

= $2\times \frac{22}{7}\times \frac{21}{2}$ = $66$ $m$

Length of rope required for fencing = $2 × 66$ $m$ = $132$ $m$
Cost of $1$ $m$ rope = Rs $4$
Cost of $132$ $m$ rope = $4 × 132$
= Rs $528$