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# Find the area of the shaded region in figure, if radii of the two concentric circles with centre O are 7 cm and 14 cm respectively and $$∠ \ AOC \ = \ 40°$$

$$= \ \frac{40}{360} \ × \ \pi \ × \ 14^2 \ - \ \frac{40}{360} \ × \ \pi \ × \ 7^2$$
$$= \ \frac{1}{9} \ × \ \frac{22}{7}(196 \ - \ 49)$$ $$= \ \frac{22}{63} \ × \ 147 \ = \ \frac{154}{3}$$cm2