Question

Giúp em với !!!!!!

Answer 1

Áp dụng tỉ số lượng giác:

\(tanC=\dfrac{AB}{AC}\Rightarrow AC=\dfrac{3}{tan30^0}=3\sqrt{3}\left(cm\right)\)

\(sinC=\dfrac{AH}{AC}\Rightarrow AH=3\sqrt{3}.sin30^0=\dfrac{3\sqrt{3}}{2}\left(cm\right)\)

Answer 2

Áp dụng HTL:

\(tanC=\dfrac{AB}{AC}\Rightarrow AC=AB:tanC=3:tan30^0=3\sqrt{3}cm\)

\(\dfrac{1}{AH^2}=\dfrac{1}{AB^2}+\dfrac{1}{AC^2}=\dfrac{1}{9}+\dfrac{1}{27}=\dfrac{4}{27}\Rightarrow AH=\sqrt{27:4}=\dfrac{3\sqrt{3}}{2}cm\)