Question

Решить два задания (задания между собой не связаны)

Answer 1

$1)BC=x\\sinA=\frac{BC}{AC}=>AC=\frac{BC}{sinA}=\frac{3x}{2\sqrt2}\\AC^2=AB^2+BC^2=\frac{9x^2}{8}=9+x^2\\\frac{x^2}{8}=9\\x^2=72\\x=6\sqrt2\\AC=\frac{3*6\sqrt2}{2\sqrt2}=9.$

$2)CD=x\\sinB=\frac{CD}{BD}=>BD=\frac{4x}{\sqrt7}\\BD^2=BC^2+CD^2\\\frac{16x^2}{7}=9+x^2\\\frac{9x^2}{7}=9\\x=\sqrt7\\BD=\frac{4\sqrt7}{\sqrt7}=4$