Question

the diameter of a circular Park is 84 metre. On its outside there a 3.5 M Wide Road. find the cost of constructing the road at rupees 240 per metre square.

please solve this question and its answer is rupees 231000

Answer 1

$<b>$
$\underline\bold{\huge{Solution!!}}$

Diameter of circular park = 84 m.

Radius of circular park = 84/2 = 42 m.

Area of circular park =

$\pi {r}^{2}$

$= \frac{22}{7} \times 42 \times 42$

$= 5544 \: {m}^{2}$

Radius of circular park with road

= 42 + 3.5

= 45.5 m.

Areaof circular park with road

$= \frac{22}{7} \times 45.5 \times 45.5$

$= 6506.5 \: {m}^{2}$

Area of road

= 6506.5 - 5544

= 962.5 Sq. meter

cost of constructing the road

= 962.5 × 240

= 23,1000 rupees.