Wire re-formed: circle (r = 56 cm) to square: A wire forms a circle of radius 56 cm. If re-bent into a square, what is the square’s area?
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A7744
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B8844
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C5544
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D4444
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ENone of these
Answer
Correct Answer: 7744
Explanation
Introduction / Context:The same wire length (perimeter) is reused: circumference of the circle becomes the perimeter of the square. From the square’s side, compute area.
Given Data / Assumptions:
- Circle radius r = 56 cm ⇒ circumference C = 2πr.
- Square perimeter = C ⇒ side = C/4.
Concept / Approach:Use π = 22/7 (standard in many aptitude problems) for exact integer results here.
Step-by-Step Solution:
C = 2 * (22/7) * 56 = 2 * 22 * 8 = 352 cm.Square side = 352/4 = 88 cm.Area = 88^2 = 7744 sq. cm.Verification / Alternative check:Using π ≈ 3.14 yields ~7729 sq. cm; with 22/7 the conventional exact result is 7744 (matches options).
Why Other Options Are Wrong:Other numbers do not align with perimeter conservation and the typical π = 22/7 convention used for tidy results.
Common Pitfalls:Forgetting to divide circumference by 4 to get the square’s side; mixing up perimeter and area formulae.
Final Answer:7744