OH-YEAH^^
Vài giây trước

Đáy BC dài số cm là

\(200\times2:25=16\left(cm\right)\)

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Áp dụng hệ thức lượng:

`@`\(\dfrac{1}{AH^2}=\dfrac{1}{AB^2}+\dfrac{1}{AC^2}\)

\(\Leftrightarrow\dfrac{1}{24^2}=\dfrac{1}{30^2}+\dfrac{1}{AC^2}\)

\(\Leftrightarrow\dfrac{1}{AC^2}=\dfrac{1}{1600}\)

\(\Leftrightarrow AC=40\left(cm\right)\)

`@`Áp dụng định lý pytago \(BC=\sqrt{30^2+40^2}=\sqrt{2500}=50\left(cm\right)\)

`@`\(AB^2=BH.BC\)

\(\Rightarrow BH=\dfrac{30^2}{50}=18\left(cm\right)\)

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ĐỨc trọng
Vài giây trước

pytago\(\Rightarrow BH=\sqrt{AB^2-AH^2}=\sqrt{30^2-24^2}=18cm\)

\(có:AB^2=BH.BC\Leftrightarrow BC=\dfrac{AB^2}{BH}=50cm\)

\(pytago\Rightarrow AC=\sqrt{BC^2-AB^2}=\sqrt{50^2-30^2}=40cm\)

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Mun SiNo
_silverlining
3 phút trước

My favorite subject is English

I am interested/ fond of/ keen on Math

What is the length of its shelves?

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Phạm Vĩnh Linh
Vài giây trước

2  Does Victoria often skate in the park?

No, she doesn't

3 Does Chris sometimes play computer games?

Yes, he does

4 Does Victoria usually stay at home?

No, she doesn't

5 Does Peter always watching TV

No, he doesn't

6 Does Sylvia often go out with friends?

No, she doesn't

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_silverlining
Vài giây trước

Does Victoria often skate in the park? - No, she doesn't 
Does Chris sometimes play computer games? - No, he doesn't
Does Victoria usually stay at home? - No, she doesn't
Does Peter always watch TV? - No, he doesn't
Does Sylvia often go out with friends? - No, she doesn't

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