Question

the radius of a circular field is 35m.on itsoutside ,there is a path 5m wide . find the cost of levelling the path at ₹5.50 per sq m.

Answer 1

radius =35 m
area= 3850sq.m
big radius=35+5. =40m
new area=5028.57sq.m
area of path=5028.57-3850
=1178.57sq.m
cost of levelling=1178.57*5.50=64821.35. rupees

Answer 2

Solution :

The radius of the circular field,

                                     r = 35 m

Now, the area of the circular field

   = πr² m²

   = π * 35² m²

   = 1225π m²

Given that, the width of the path is 5 m

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

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

  = 35 + 5 m

  = 40 m

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

   = π (40)² m²

   = 1600π 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

   = (1600π - 1225π) m²

   = 375π m²

Thus, the cost of levelling the path at Rs 5.50 per m²

  = Rs (5.50 * 375π)

  = Rs (5.50 * 375 * 22 / 7)

  = Rs 6482.14