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AP EAMCET · Maths · Properties of Triangles

In a \(\triangle A B C\), if \(\angle A=60^{\circ}\), then \((a+b+c)(b+c-a)=\)

  1. A \(3 b c\)
  2. B \(2 a b c\)
  3. C \(a b c\)
  4. D \(a+b+c\)
Verified Solution

Answer & Solution

Correct Answer

(A) \(3 b c\)

Step-by-step Solution

Detailed explanation

In \(\triangle A B C\), \(\angle A=60^{\circ}, \angle B+\angle C=180^{\circ}-\angle A=120^{\circ}\) \(a=k \sin A, b=k \sin B, c=k \sin C\) (sine rule) Now, \((b+c+a)(b+c-a)\)…