9th Class Mathematics Circles Question Bank Circles

  • question_answer
    In the given figure, AEDF is a cyclic quadrilateral. The values of \[x\] and y respectively are          

    A) \[{{79}^{o}},\,\,{{47}^{o}}\]

    B)        \[{{89}^{o}},\,\,{{37}^{o}}\]

    C)                    \[{{89}^{o}},\,\,{{47}^{o}}\]

    D)        \[{{79}^{o}},\,\,{{37}^{o}}\]

    Correct Answer: B

    Solution :

    In \[\Delta \Alpha \Epsilon \Beta ,\angle ABE+\angle BEA+BAE={{180}^{o}}\] \[\Rightarrow \]\[{{35}^{o}}+\angle BEA+{{54}^{o}}={{180}^{o}}\] \[\Rightarrow \]\[\angle BEA={{91}^{o}}\] Now, \[\angle AFD+\angle DEA={{180}^{o}}\] (opposite angles of cyclic quadrilateral) \[\Rightarrow \]\[x+{{91}^{o}}={{180}^{o}}\Rightarrow x={{89}^{o}}\] In \[\Delta AFC,\angle AFC+\angle FCA+\angle CAF={{180}^{o}}\] \[\Rightarrow \]\[{{89}^{o}}+y+{{54}^{o}}={{180}^{o}}\Rightarrow y={{37}^{o}}\]


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