Question

The area of a circular park is 616$m^2$ . There is a 3.5$m$ wide track around the park ruming parallel to the boundary. Calculate the cost of fencing on the outer circle af the rate of $rs5$ per meter.

Answer 1

The area of circular park is $616m^2$

$⟹\pi r^2=616r^2=616\times \frac{7}{22}=196r=14cm$

the wide track is of width $3.5m$

Radius of outer circle is $14+3.5=17.5m$

The circumerence is $2\pi r2\times \frac{22}{7}\times 17.522\times 2.5=110m^2$

The cost of fencing is $5\times 110=550Rs.$