JEE Math Practice Question
For a triangle $$ABC$$, the value of $$\cos 2A + \cos 2B + \cos 2C$$ is least. If its inradius is 3 and incentre is M, then which of the following is NOT correct?
- A.$$\overrightarrow {MA} \,.\,\overrightarrow {MB} = - 18$$
- B.$$\sin 2A + \sin 2B + \sin 2C = \sin A + \sin B + \sin C$$
- C.perimeter of $$\Delta ABC$$ is 18$$\sqrt3$$
- D.area of $$\Delta ABC$$ is $${{27\sqrt 3 } \over 2}$$
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