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cloverkumaon
3 tháng trước

*các bạn giải thích chi tiết cách làm và đáp án nhe. Cho tam giác ABC vuông tại A, đường cao AH. Biết AB = 15 cm, BC = 25 cm. Tính BH và AH

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Nguyễn Quân
3 tháng trước

Đáp án+Giải thích các bước giải:

Xét `∆ABC` vuông tại `A` có `AH⊥BC(g t)`. Áp dụng hệ thức lượng ta có:

`=>{(AB^2=BH.BC),(AH^2=BH.CH):}`

`<=>{(15^2=BH.25),(AH^2=BH.(BC-BH)):}`

`<=>{(BH=15^2:25),(AH^2=BH.(BC-BH)):}`

`<=>{(BH=9),(AH^2=9.(25-9)):}`

`<=>{(BH=9),(AH^2=144):}`

`<=>{(BH=9cm),(AH=12cm):}`

Vậy `BH=9cm,AH=12cm`

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