Bài 5:
AB<AC
nên \(\widehat{C}< \widehat{B}\)
=>\(\widehat{ADB}< \widehat{ADC}\)
P/s: Mình tự làm nên sai thì cho mình xin lỗi ạ!
\(\text{Bài 5:}\)
\(\text{Ta có:}\widehat{ADB}=\widehat{DAC}+\widehat{DCA}\text{(góc ngoài)}\)
\(\widehat{ADC}=\widehat{DAB}+\widehat{ABD}\text{(góc ngoài)}\)
\(\text{Do AD là phân giác }\widehat{A}\)
\(\Rightarrow\widehat{DAC}=\widehat{DAB}\)
\(\text{mà }AB< AC\)
\(\Rightarrow\widehat{ACD}< \widehat{ABD}\)
\(\Rightarrow\widehat{ADB}< \widehat{ADC}\)
Bài 6 mik ko bt:<