Question

the circumference of a circular garden is 88m it is surrounded by a path of uniform width 3.5 m.Find the cost gravelling the path at the rate of Rs 20 per mete

Answer 1

Answer:

The answer is 24pi.

As you can see there are two concentric circles (i.e. with same centre). Let the radius of outer circle be R and inner circle be r.

r = 10/2 = 5m

R = 5 (radius of inner circle) + 2 (width of the path) = 7m

Area of the path = Area of Outer circle - Area of Inner circle

= pi * (R)^2 - pi * (r)^2

= pi * (7)^2 - pi * (5)^2

= 49* (pi) - 25* (pi)

= 24pi