Đáp án:
AB=6,56 cm
AC=7,46 cm
Giải thích các bước giải:
\(\widehat{A}=180°-45°-60°=75°\)
Định lí Sin: \(\frac{BC}{Sin A}=\frac{AC}{Sin B}\)
\(\leftrightarrow \frac{9}{Sin 75}=\frac{AC}{Sin 60}\)
\(\leftrightarrow \frac{9\sqrt{3}}{2}=\frac{\sqrt{6}+\sqrt{2}}{4}.AC\)
\(\leftrightarrow AC=7,46\) cm
Ta có: \(\frac{AB}{Sin C}=\frac{BC}{Sin A}\)
\(\leftrightarrow \frac{AB}{Sin 45}=\frac{9}{Sin 75}\)
\(\leftrightarrow AB.\frac{\sqrt{6}+\sqrt{2}}{4}=9\frac{\sqrt{2}}{2}\)
\(\leftrightarrow AB=6,56\) cm
