TS EAMCET · Maths · Properties of Triangles
If the perimeter of the triangle \(A B C\) is \(50 \mathrm{~cm}\), then \(b \cos ^2 \frac{C}{2}+c \cos ^2 \frac{B}{2}=\)
- A \(20\)
- B \(25\)
- C \(30\)
- D \(35\)
Answer & Solution
Correct Answer
(B) \(25\)
Step-by-step Solution
Detailed explanation
Since, \(b \cos ^2 \frac{C}{2}+c \cos ^2 \frac{B}{2}\) \(\begin{aligned} & =\frac{1}{2}\left[b\left(2 \cos ^2 \frac{C}{2}\right)+c\left(2 \cos ^2 \frac{B}{2}\right)\right] \\ & =\frac{1}{2}[b(1+\cos C)+c(1+\cos B)]\end{aligned}\)…
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