In the give figure, the sectors of two concentric circles of radii 7 cm and 3.5 cm are shown. Find the area of the shaded region.

Given,


Radius of smaller circle = R1 = 3.5 cm


Radius of bigger circle = R2 = 7 cm


Angle subtended = 30°



Area of Shaded region = =


= 22/7 × (72 – 3.52) × 30/360 cm2


= 22/7 × (49 – 12.22) × θ/360 cm2


= 9.625 cm2


Area of shaded region = 9.625 cm2


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