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Question
In fig.DE || BC ,AD = 1 cm and BD = 2 cm. what is the ratio of the ar(ΔABC) to the ar (ΔADE)?
Solution
DE || BC
ΔADE ΔABC [By AA similarity]
`∴ (ar (DeltaABC))/(ar(DeltaADE)) = (AB^2)/(AD^2)` [By area similarity theorem]
`⇒ (ar (DeltaABC))/(ar(DeltaADE)) = 3^2/1^2`
`⇒ (ar (DeltaABC))/(ar(DeltaADE)) = 9/1`
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