Question

are 6 m wide path is to be constructed all around and outside of a circular field of diameter 126 M find the cost of constructing the path at Rs 5
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Answer 1

Solution :

The diameter of the circular field,

                                      d = 126 m

So, its radius,

          r = d /2 = 126 / 2 m = 63 m

Now, the area of the circular field

    = πr² m²

    = π * 63² m²

    = 3969π m²

Given that, the width of the path is 6 m

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

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

    = 63 + 6 m

          = 69 m

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

    = π (69)² m²

    = 4761π 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

    = (4761π - 3969π) m²

    = 792π m²

Thus, the cost of constructing the path at Rs 5 per m²

  = Rs (5 * 792π)

     = Rs (3960π)

        = Rs (3970 * 22 / 7)

           = Rs 12445.71

Answer 2

here is your answer

Given,

radius of circular field= OA = 126/2=63m

(r1)

radius of the circle with radius 0B= 63+ 6 =69m

(r2)

refer to the attachment for diagram

Remember,

area of circle = πr^2

Now, According to the attachment=>>

area of path = area of circular field-

area of circle with radius OB

=> π(r2)^2 - π(r1)2

=>π{(r2)^2 - (r1)^2}

=>π{(69)^2 - (63)^2}

=>π(4761-3969)

=>π(792) m^2

Hence,area of path is π(792) m^2.

Now,

cost of constructing 1m^2 path =Rs 5

So,

cost of constructing 792π m^2 path is

= (792 × 5 ×22)/7

=(87,120)/7

=Rs12445.714

So cost of constructing 792 m^2 path is

Rs12445.714.

hope it helps

BE BRAINLY///