Question

Answer 1

Ta có : \(AB\backslash\backslash CD\)

\(\Leftrightarrow\widehat{A}+\widehat{ACD}=180^0\)(2 góc trong cùng phía)

Mà \(\widehat{A}=40^o\)

\(\Leftrightarrow\widehat{ACD}=140^o\) 

Lại có :

 \(CD\backslash\backslash EG\)

\(\Leftrightarrow\widehat{E}=\widehat{HCE}\) (2 sóc so le trong) 

\(AB\backslash\backslash CD\Leftrightarrow\widehat{A}=\widehat{ACH}\) (2 góc so le trong)

Mà : \(\widehat{ACE}=\widehat{HCE}+\widehat{ACH}=90^o\)