The radii of two concentric circles are 68 cm and 22 cm. The area of the closed figure bounded by the boundaries of the circles is:
Show answer & explanation
Correct answer: A
Explanation
The correct answer is Option 1 i.e. 4140π sq. cm
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Understanding |
Application |
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We know that: Area of a circle = πr2 The radii of two concentric circles are 68 cm and 22 cm. |
So, The area of the closed figure bounded by the boundaries of the circles = π × (r12 – r22) = π × (682 – 222) = π × (68 + 22) × (68 – 22) = π × 90 × 46 = 4140π sq. cm |