A) \[10\sqrt{2}\]
B) \[5\]
C) \[5\sqrt{2}\]
D) \[20\]
Correct Answer: D
Solution :
\[\frac{\cos A}{a}=\frac{\cos B}{b}=\frac{\cos C}{c}\] \[\Rightarrow \] \[\frac{\cos A}{k\sin A}=\frac{\cos B}{k\sin B}=\frac{\cos C}{k\sin C}\](by Sine rule) \[\Rightarrow \] \[\cot A=\cot B=\cot C\] \[\Rightarrow \] \[A=B=C=60{}^\circ \] \[\therefore \]\[\Delta ABC\]is equilateral. Thus, area\[\Delta ABC=\frac{\sqrt{3}}{4}{{(side)}^{2}}\] \[=\frac{\sqrt{3}}{4}.4=\sqrt{3}\]
You need to login to perform this action.
You will be redirected in
3 sec
