Solution:
Radius of big circle (R) = 7cm∴ Area of big circle = πR2
⇒ Area of big circle = × (7) 2
∴ Area of big circle = 154 cm2-- ( 1 )
now,
⇒ Radius of small circle (r)= 72 = 3.5
Area of smaller circle =πr2
⇒ Area of small circle = × (3.5) 2
∴ Area of small circle = 38.5 cm2 -- ( 2 )
⇒ Area of shaded region = Area of big circle - Area of small circle.
⇒ Area of shaded region =154−38.5 = 115.5 cm
Hence the required area of the shaded region is
So, the correct answer is “115.5 cm2”.
