Question

Решите одну хотябы задачуууу

Answer 1

$2705)quad textless C=90^circ ; ,; ; tgA= frac{2sqrt{21}}{21} ; ,; ; BC=6; ,; ; AB=?\\tgA= frac{BC}{AC} = frac{2sqrt{21}}{21} ; ; to ; ; AC= frac{21 cdot BC}{2sqrt{21}} = frac{21cdot 6}{2sqrt{21}} =3sqrt{21}\\AB=sqrt{AC^2+BC^2}=sqrt{9cdot 21+36}=sqrt{225}=15\\\2712)quad textless C=90^circ ; ,; ; cosA=frac{3}{5}; ,; ; AB=25; ,; ; AH=?\\cosA= frac{AC}{AB}= frac{3}{5} ; ; to; ; AC= frac{3cdot AB}{5}=frac{3cdot 25}{5} =15$

$AC^2=AHcdot AB; ; to ; ; AH=frac{AC^2}{A}=frac{15^2}{25}=9$