Class 11MathematicsTrigonometrical EquationsRelation between sides and angles, Solutions of triangles
MediumIn triangle $ABC$,if $a=7, b=8, \cos C=\frac{2}{7}$ and $C$ is an acute angle,then $c=$
- A$\sqrt{145}$
- B$5$
- C$11$
- D$9$
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