A square and an equilateral triangle are inscribed in a circle. If a and b…

2024

A square and an equilateral triangle are inscribed in a circle. If a and b denote the lengths of their sides respectively, then which of the following is true?

  1. A.

    2a2 = 3b2

  2. B.

    3a2 = 2b2

  3. C.

    a2 = 3b2

  4. D.

    b2 = 2a2

Attempted by 4 students.

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Correct answer: B

Let the radius of the circle be r.

For a square inscribed in a circle, the diagonal equals the diameter. So, diagonal = a√2 = 2r. Therefore, a = 2r/√2 = r√2. Squaring both sides, a² = 2r².

For an equilateral triangle inscribed in a circle, the side length b is related to the radius by b = r√3. Squaring both sides, b² = 3r².

Now, compare a² and b²: a² = 2r² and b² = 3r². So, a²/b² = 2/3, which implies 3a² = 2b².

हिन्दी उत्तर:

माना वृत्त की त्रिज्या r है।

एक वर्ग के लिए, विकर्ण वृत्त के व्यास के बराबर होता है। अतः विकर्ण = a√2 = 2r, जिससे a = 2r/√2 = r√2। दोनों ओर वर्ग करने पर, a² = 2r²।

एक समबाहु त्रिभुज के लिए, भुजा b त्रिज्या r से संबंधित होती है: b = r√3। दोनों ओर वर्ग करने पर, b² = 3r²।

अब a² और b² की तुलना करें: a² = 2r² और b² = 3r²। अतः a²/b² = 2/3, जिससे 3a² = 2b² प्राप्त होता है।

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