Question

A road which is 7m wide surrounds a circular park whose circumference is 352m. Find the area of road.

Answer 1

Outer radius of road = R

Inner radius of road = r

Width of park road = d

R = 2 + d

Circumference of road (outer) = 2𝜋R

2𝜋R = 352 [from problem given]

`2 ×22/7× R = 352`
`R =352×7/2×22= 56m`

Inner radius = R – d = 56 – 7 = 49 m

Area of road = π(R² − r²)

`=22/7(63^2 − 56^2)`

= `22/7(3969 − 3136)`

= `22/7 xx 833`

= `18326/7`

= `2618m^2`