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If A,B,C are the angles of a triangal ,p...

If A,B,C are the angles of a triangal ,prove that : cos A +cos B + cos `C = 1+r/R`

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To prove that \( \cos A + \cos B + \cos C = 1 + \frac{r}{R} \) for a triangle with angles \( A, B, C \), we can follow these steps: ### Step 1: Start with the left-hand side (LHS) We begin with the expression: \[ \text{LHS} = \cos A + \cos B + \cos C \] ...
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