2. Solved Papers
  3. BCECE Engineering

BCECE Engineering BCECE Engineering Solved Paper-2015

  • question_answer
    The exradii of a triangle, \[{{r}_{1}},{{r}_{2}},{{r}_{3}}\]are in 1A armonic progression, then the sides a, b and c are in

    A) HP                                        

    B) AP

    C) GP                                           

    D) None of these

    Correct Answer: B

    Solution :

    It is given that \[{{r}_{1}},{{r}_{2}}\]and \[{{r}_{3}}\]are in HP. \[\Rightarrow \]               \[\frac{2}{{{r}_{2}}}=\frac{1}{{{r}_{1}}}+\frac{1}{{{r}_{3}}}\] \[\Rightarrow \]               \[\frac{2(s-b)}{\Delta }=\frac{s-a}{\Delta }+\frac{s-c}{\Delta }\] \[\Rightarrow \]               \[2a-2b=2s-a-c\] \[\Rightarrow \]               \[2b=a+c\] Hence, a, b and c are in AP


You need to login to perform this action.
You will be redirected in 3 sec spinner