Question

Bt AB//CD , CD//EF

a) tính ACD và DCE 

b) Tính ACE 

Cho mik xin lời giải nữa ạ

 

Answer 1

a) Ta có: AB//CD 

\(\widehat{A_1}=\widehat{BAC}\)

\(\Rightarrow\widehat{BAC}=110^o\) 

Mà: \(\widehat{BAC}+\widehat{ACD}=180^o\)

\(\Rightarrow\widehat{ACD}=180^o-110^o=70^o\) 

Lại có: CD//EF 

\(\Rightarrow\widehat{DCE}+\widehat{CEF}=180^o\)

\(\Rightarrow\widehat{DCE}=180^o-150^o=30^o\)

b) Mà: \(\widehat{ACE}=\widehat{ACD}+\widehat{DCE}\)

\(\Rightarrow\widehat{ACE}=30^o+70^o=100^o\)