Question

giúp mk vs ạ, mk cảm tạ ạ

Answer 1

Có \(\widehat{B}+\widehat{C}=180^0\)(Hai góc kề bù do AB//CD)

mà \(\widehat{B}-\widehat{C}=40^0\) 

\(\Rightarrow\widehat{B}=\dfrac{180^0+40^0}{2}=110^0\); \(\widehat{C}=\dfrac{180^0-40^0}{2}=70^0\)

Có \(\widehat{A}+\widehat{D}=180^0\)(Hai góc kề bù do AB//CD)

mà \(\widehat{A}=2\widehat{D}\)\(\Rightarrow\widehat{2D}+\widehat{D}=180^0\)\(\Leftrightarrow\widehat{D}=60^0\)

\(\Rightarrow\widehat{A}=120^0\)

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