Question

a circular field of radius 14 metre has a path 1.75 M wide running around it and the cost of gravelling the path at rupees 10 per square metre​

Answer 1

Solution :

The radius of the circular field,

                                     r = 14 m

Now, the area of the circular field

   = πr² m²

   = π * 14² m²

   = 196π m²

Given that, the width of the path is 1.75 m

Now, the radius of the circular field along with the path around it

  = (radius of the circular field) + (width of the path)

  = 14 + 1.75 m

  = 15.75 m

So, the area of the of the circular field along with the path around it

   = π (15.75)² m²

   = 248.0625π m²

Thus, the area of the path

= (the area of the circular field along with the path around it) - (the area of the circular field) m²

   = (248.0625π - 196π) m²

   = 52.0625π m²

Thus, the cost of gravelling the path at Rs 10 per m²

 = Rs (10 * 52.0625π)

    = Rs (520.625π)

       = Rs (520.625 * 22 / 7)

          = Rs 1636.25

Answer 2

Here is your answer

Given,

radius of circular field = 14m(OA)(r1)

Width of the path = 1.75m(AD)

REFER TO ATTACHMENT for diagram

So ,

radius OD = 14+1.75 =15.75 m(r2)

Remember,

area of circle = πr^2

Now, According to question

area of gravel path =

area of circle with radius OD -

area of circle with radius OA

=> π(r1)^2 - π( r2)^2

=>π{(r1)^2 - (r2)^2}

=>π{(15.75)^2 - (14)^2}

=>π(248.0625 - 196)

=>π(52.0625)

=>(22×52.0625)7 (since π =22/7)

=>163.625 m^2

hence area of the path is 163.625 m^2.

Now, cost of gravelling per square meter path = Rs 10

So, Cost of gravelling the163.625 m^2 path

= 163.625 × 10

=Rs1636.25

hence ,cost of gravelling the path is Rs1636.25.

hope it helps

BE BRAINLY//