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In an equilateral triangle ABC, D is a p...

In an equilateral triangle ABC, D is a point on side BC such that `B D=1/3B C`. Prove that `9A D^2=7A B^2`.

Text Solution

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In` ΔABC` as shown in the figure
`(AB)= (BC)= (CA) and (BD) = 1/3 (BC)`
Draw `AE ⊥ BC` ...
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