Question

vẽ tam giác ABC vuông tại A, Dường cao AH. Hãy tính AB,AC,BC,CH hoặc BH trong các trường hợp sau

1)AB=3cm;AC=5cm

1)AB=√3cm;AC=3cm

1)AB=2√3cm;AC=3cm

Answer 1

1: \(BC=\sqrt{3^2+5^2}=\sqrt{34}\left(cm\right)\)

\(AH=\dfrac{AB\cdot AC}{BC}=\dfrac{15\sqrt{34}}{34}\left(cm\right)\)

\(BH=\dfrac{AB^2}{BC}=\dfrac{9\sqrt{34}}{34}\left(cm\right)\)

\(CH=BC-BH=\dfrac{25\sqrt{34}}{34}\left(cm\right)\)

2: \(BC=\sqrt{3+9}=2\sqrt{3}\left(cm\right)\)

\(AH=\dfrac{AB\cdot AC}{BC}=\dfrac{3\sqrt{3}}{2\sqrt{3}}=1.5\left(cm\right)\)

\(BH=\dfrac{AB^2}{BC}=\dfrac{3}{2\sqrt{3}}=\dfrac{\sqrt{3}}{2}\left(cm\right)\)

\(CH=BC-BH=2\sqrt{3}-\dfrac{1}{2}\sqrt{3}=\dfrac{3\sqrt{3}}{2}\left(cm\right)\)