Question

In fig., PQ and AB are respectively the arcs of two concentric circles of radii 7 cm and 3.5 cm and centre O. If $∠$ POQ = 30⁰, then find the area of the shaded region.

Solution

Area of the shaded region = Area of the sector POQ - Area of the sectos AOB

$Area of shaded region = (\frac{θ}{360} π R^{2} - \frac{θ}{360} π r^{2}) = \frac{θ}{360} π (R^{2} - r^{2}) = \frac{30}{360} x \frac{22}{7} x (7^{2} - (3.5)^{2}) = \frac{1}{12} x \frac{22}{7} x (49 - 12.25) = \frac{22}{12 x 7} x 36.75 = \frac{77}{8} {cm}^{2}$

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In fig., PQ and AB are respectively the arcs of two concentric circles of radii 7 cm and 3.5 cm and centre O. If $∠$ POQ = 30⁰, then find the area of the shaded region.

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Areas Related To Circles

In fig., PQ and AB are respectively the arcs of two concentric circles of radii 7 cm and 3.5 cm and centre O. If ∠POQ = 300, then find the area of the shaded region.

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In fig., PQ and AB are respectively the arcs of two concentric circles of radii 7 cm and 3.5 cm and centre O. If $∠$ POQ = 30⁰, then find the area of the shaded region.