2. Questions Bank
  3. JEE Main & Advanced
  4. Mathematics
  5. Trigonometric Equations

JEE Main & Advanced Mathematics Trigonometric Equations Question Bank Relation between sides and angles, Solutions of triangles

  • question_answer
    In a\[\Delta ABC,\]if \[b=20,c=21\]and \[\sin A=3/5\], then \[a=\] [EAMCET 2003]

    A) 12

    B) 13

    C) 14

    D) 15

    Correct Answer: B

    Solution :

    \[{{a}^{2}}={{b}^{2}}+{{c}^{2}}-2bc\cos A\]Þ  \[{{a}^{2}}\]\[={{(20)}^{2}}+{{(21)}^{2}}-2.20.21.\frac{4}{5}=169\] Þ \[a=13.\]


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