Question

Two concentric circles are drawn such
that there is a uniform width of 2 cm
between them. If the area of the inner
circle is 251 cm”, find the circumference
of the outer circle in terms of pi.​

Answer 1

Radius of the circular garden, r=

2

210

=105m

Radius of the region covering the garden and the path, R=105m+7m=112m

Area of the region between two concentric circles

with radius of outer circle R, and inner circle r =π(R

2

−r

2

)

Hence, the area of the path =π(112

2

−105

2

)=

7

22

(12544−11025)=

7

33418

=4774m

2