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 240m square

Answer 1

2r=84m (given)
r =84/2=42m

outer circle's radius=42+3.5=45.5m
inner circle's radius=42m

area of path = (area of outer circle) - (area of inner circle)

cost of constructing the road is =240×area of path.