ExamBro
ExamBro
TS EAMCET · Maths · Properties of Triangles

In triangle \(\mathrm{ABC}\), if \(a=7, b=8, \mathrm{C}=\frac{3 \sqrt{5}}{2}\) and \(\mathrm{C}\) is an acute angle, then \(c=\)

  1. A \(\sqrt{145}\)
  2. B 5
  3. C 11
  4. D 9
Verified Solution

Answer & Solution

Correct Answer

(D) 9

Step-by-step Solution

Detailed explanation

\begin{aligned} & \text { } \tan \mathrm{c}=\frac{3 \sqrt{5}}{2} \\ & \Rightarrow \cos \mathrm{C}=\frac{2}{7} \\ & \cos \mathrm{c}=\frac{\mathrm{a}^2+\mathrm{b}^2-\mathrm{c}^2}{2 \mathrm{ab}} \\ & \Rightarrow \frac{2}{7}=\frac{49+64-\mathrm{c}^2}{2.7 .8} \\ & \Rightarrow…