Question

The diameter of a circular Park is 84m.On its outside there a 3.5m wide road. Find the cost of constructing the road at rupees 240 per metre square

Answer 1

radius of park = 42m
radius of park including road = 45.5 m
area of road = = π (45.5*45.5-42*42) = 898.82m^2

cost of construction = 898.82*240 = rs. 215817

Answer 2

Answer:

Rs.230790

Step-by-step explanation:

Diameter of circular park = 84 m

Radius (r)= $\frac{Diameter}{2} =\frac{84}{2} =42 m$

Since we are given that On its outside there a 3.5m wide road

So, Radius of circular park including road(R) = 42+3.5 =45.5 m

So, area of road = $\pi (R^{2} -r^{2})$

                           = $3.14(45.5^{2} -42^{2})$

                           = $961.625$

Thus the area of road is 961.625 m^2

Cost of constructing road 1 m square road = 240

Cost of constructing road 961.625 m square road = 240 *961.625

                                                                                  = Rs.230790

Hence the cost of constructing the road is Rs.230790