In the given figure, the area enclosed between two concentric circles is 808.5 cm². The circumference of the outer circle is 242 cm. Calculate :
(i) the radius of the inner circle,
(ii) the width of the ring.

Question

In the given figure, the area enclosed between two concentric circles is 808.5 cm². The circumference of the outer circle is 242 cm. Calculate :
(i) the radius of the inner circle,
(ii) the width of the ring.

KnowledgeBoat · Accepted Answer

Let R be the radius of outer circle and r be the radius of inner circle. (i) Given, Circumference of outer circle = 242 cm. Area enclosed between two concentric circles = Area of bigger circle - Area of smaller circle = πR2 - πr2 = π(R2 - r2) Given, Area enclosed between two concentric circles = 808.5 cm2 ⇒ 808.5 = (R2 - r2) ⇒ (38.5)2 - r2 = ⇒ 1482.25 - r2 = ⇒ 1482.25 - r2 = 257.25 ⇒ r2 = 1482.25 - 257.25 ⇒ r2 = 1225 ⇒ r = = 35 cm. Hence, radius of inner circle = 35 cm. (ii) Width of ring = R - r = 38.5 - 35 = 3.5 cm. Hence, width of the ring = 3.5 cm.

Mathematics

In the given figure, the area enclosed between two concentric circles is 808.5 cm². The circumference of the outer circle is 242 cm. Calculate :
(i) the radius of the inner circle,
(ii) the width of the ring.

Mensuration

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Mathematics

In the given figure, the area enclosed between two concentric circles is 808.5 cm2. The circumference of the outer circle is 242 cm. Calculate :(i) the radius of the inner circle,(ii) the width of the ring.

Mensuration

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In the given figure, the area enclosed between two concentric circles is 808.5 cm². The circumference of the outer circle is 242 cm. Calculate :
(i) the radius of the inner circle,
(ii) the width of the ring.

The areas of two concentric circles are 962.5 cm² and 1386 cm² respectively. Find the width of the ring.

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