Question

Cho \(\Delta ABC\) có \(\widehat{A}=50^0;\widehat{B}:\widehat{C}=2:3\). So sánh các cạnh của \(\Delta ABC\)

Answer 1

@Phạm Hoàng Giang

Answer 2

@trần anh tú

Answer 3

Hình:

Có: \(\widehat{B}:\widehat{C}=2:3\Rightarrow\dfrac{\widehat{B}}{2}=\dfrac{\widehat{C}}{3}\)

và \(\widehat{B}+\widehat{C}=180^o-\widehat{A}=180^o-50^0=130^o\)

Áp dụng tccdts= nhau có:

\(\dfrac{\widehat{B}}{2}=\dfrac{\widehat{C}}{3}=\dfrac{\widehat{B}+\widehat{C}}{2+3}=\dfrac{130}{5}=26\)

\(\Rightarrow\widehat{B}=26\cdot2=52^o;\widehat{C}=26\cdot3=78^o\)

=> \(\widehat{A}< \widehat{B}< \widehat{C}\Rightarrow BC< AC< AB\)