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प्रश्न
In an equilateral triangle ABC if AD ⊥ BC, then
विकल्प
5AB2 = 4AD2
3AB2 = 4AD2
4AB2 = 3AD2
2AB2 = 3AD2
उत्तर
∆ABC is an equilateral triangle and `AD ⊥ BC`.
In ∆ABD, applying Pythagoras theorem, we get
`AB^2=AD^2+BD^2`
`AB^2=AD^2+(1/2BC)^2(∵BD=1/2BC)`
`AB^2=AD^2+(1/2AB)^2(∵ AB=BC)`
`AB^2=AD^2+1/2AB^2`
`3AB^2=4AD^2`
We got the result as `b`.
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