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If in DeltaABC,A=(pi)/(7),B=(2pi)/(7),C=...

If in `DeltaABC,A=(pi)/(7),B=(2pi)/(7),C=(4pi)/(7)` y then `a^(2)+b^(2)+c^(2)` must be

A

`R^(2)`

B

`3R^(2)`

C

`4R^(2)`

D

`7R^(2)`

Text Solution

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The correct Answer is:
D
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