Incised square — A circle has circumference 25 cm. Find the side of a square inscribed inside it.
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A25/(π√2) cm
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B21/(π√3) cm
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C23/(π√2)
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D29/(π√3) cm
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E25/(2π) cm
Answer
Correct Answer: 25/(π√2) cm
Explanation
Introduction / Context:For a square inscribed in a circle, the square’s diagonal equals the circle’s diameter. If we know the circumference, we can find the radius/diameter and hence the square’s side.
Given Data / Assumptions:
- Circumference C = 25 cm
- 2πr = 25 ⇒ r = 25/(2π)
- Diameter D = 2r = 25/π
- Inscribed square side s = D/√2 = (25/π)/√2
Concept / Approach:Use the relation between an inscribed square and its circumcircle (the given circle). Side is diagonal divided by √2.
Step-by-Step Solution:s = (25/π)/√2 = 25/(π√2) cm
Verification / Alternative check:Compute the square’s diagonal s√2 = 25/π, matching the circle’s diameter as required.
Why Other Options Are Wrong:Other expressions use wrong radicals or constants; only 25/(π√2) follows from geometry.
Common Pitfalls:Using the radius instead of the diameter for the square’s diagonal; missing the √2 relationship.
Final Answer:25/(π√2) cm