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TS EAMCET · Maths · Properties of Triangles

In \(\triangle A B C\), if \(a, b, c\) are in arithmetic progression and \(\mathrm{A}=2 \mathrm{C}\), then \(\mathrm{b}: \mathrm{c}=\)

  1. A \(4: 5\)
  2. B \(2: 3\)
  3. C \(5: 4\)
  4. D \(5: 6\)
Verified Solution

Answer & Solution

Correct Answer

(C) \(5: 4\)

Step-by-step Solution

Detailed explanation

\(a, b, c\) are in AP \(\Rightarrow \sin \mathrm{A}, \sin \mathrm{B}, \sin \mathrm{C}\) are in \(\mathrm{AP}\) \(\Rightarrow \quad 2 \sin \mathrm{B}=\sin \mathrm{A}+\sin \mathrm{C}\) \(\Rightarrow \quad 2 \sin B=\sin 2 C+\sin C \quad[\because A=2 C]\)…