Question

in figure are two concentric circles with a have radius 21 cm and 42 CM if angleAOB equals to 60 degree find the area of the shaded region

Answer 1

Hope it will help you......
the answer is 3465cm^2
for solution see the above image

Answer 2

HERE IS YOUR ANSWER:

THETA = 60°
r1 = 21 cm
r2 = 42cm
Reflex angle OAB = 360° - 60°
= 300°

A of sector 1 = Theta/ 360° x π r1²
= 300/360 x 22/7 x 21 x 21
= 5/6 x 22 x 3 x 21
= 5 x 11 x 21
= 1155 cm²
A ofs sector 2 = 300/360 x 22/7 x 42 x 42
= 5/6 x 22 x 6 x 42
= 5 x 22 x 42
= 4620 cm²
A of shaded region = A of sector 2 - A of
sector 1
= 4620 - 1155
= 3465 cm²

HOPE IT HELPS YOU.
PLZ MARK THIS ANSWER AS BRAINLIEST