Question

the radius of a circular Park is 56 metre if a road 3.5 metre wide is made around its on the outside find the cost of construction The Road at the rate of rupees 25 per square meter​

Answer 1

First the area of the circular park
= Pi r^2
=22/7*56^2
=22/7*3136
=22*448
=9856 metre square

Area of park along with road
Then radius of park along with the road
=56+3.5
=59.5metres

Therefore area of park along with the road
= Pi r^2
=3.14*59.5^2
=3.14*3540.25
=11116.385 metre square

Therefore the area of the road =
Area of park along with the road -area of park

=11116.385-9856
=1260.385 metre square

Cost of construction of road
=area of road *25
=1260.385*25
=Rs. 31509.625