ExamBro
ExamBro
TS EAMCET · Maths · Properties of Triangles

If, in a \(\triangle A B C, \tan \frac{A}{2}=\frac{5}{6}\) and \(\tan \frac{C}{2}=\frac{2}{5}\), then \(a, b, c\) are such that :

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

Answer & Solution

Correct Answer

(B) \(2 b=a+c\)

Step-by-step Solution

Detailed explanation

\(\because \quad \tan A=\frac{5}{6}\) and \(\tan C=\frac{2}{5}\) \(\therefore \quad \tan A \tan C=\frac{5}{6} \cdot \frac{2}{5}\) \(\Rightarrow \quad \frac{s-b}{s}=\frac{1}{3}\) \(\Rightarrow \quad 3 s-3 b=s\) \(\Rightarrow \quad 2 s=3 b\) \(\Rightarrow \quad a+c=2 b\)