Question

the diameter of a circular Park is 84m. A 3.5m wide toad runs on the outside around it. Find the cost of constructing the road at rupees 20 per square metre.

plz answer fast

Answer 1

radius of park x =84/2 =42 m
radius of outer circle y = 42 +3.5 =45.5m
area of road=
$\pi( {y}^{2} - {x}^{2} ) \\ \pi( {45.5}^{2} - {42}^{2} ) \\ \frac{22}{7} (2070.25 - 1764) \\ \frac{22}{7} \times 306.25 \\ 962.25 {m}^{2}$
cost of construction =20×962.25
= rs 19245

Answer 2

Answer:

The cost of constructing road is Rs.19245.

Step-by-step explanation:

Given : The diameter of a circular Park is 84 m. A 3.5 m wide toad runs on the outside around it.

To find : The cost of constructing the road at rupees 20 per square meter?

Solution :

Diameter of the park = 84 m

Let the radius of the park be x=42 m

Radius of outer circle y = 42 +3.5 =45.5 m

Area of road is

$A=\pi({y}^{2} - {x}^{2})\\\\A= \pi( {45.5}^{2} - {42}^{2})\\\\A=\frac{22}{7}(2070.25 - 1764)\\\\A=\frac{22}{7} \times 306.25\\\\ A=962.25 {m}^{2}$

The area of the road is 962.25 meter square.

Rate = Rs.20 per square metre.

Cost of construction is

$C=20\times962.25= Rs.19245$

Therefore, The cost of constructing road is Rs.19245.