Question

Answer 1

Câu 1:

a) Ta có: d//d', AB⊥d

=> AB⊥d'(từ vuông góc đến song song)

b) Ta có: \(\widehat{E_2}=\widehat{E_1}=45^0\)(đối đỉnh)

c) Ta có: d//d'

\(\Rightarrow\widehat{F_1}+\widehat{E_1}=180^0\)(trong cùng phía)

\(\Rightarrow\widehat{F_1}=180^0-\widehat{E_1}=180^0-45^0=135^0\)

\(\Rightarrow\widehat{F_2}=\widehat{F_1}=135^0\)(đối đỉnh)

Bài 2:

Ta có: a⊥MN,b⊥MN

=> a//b

\(\Rightarrow\left\{{}\begin{matrix}\widehat{ABN}+\widehat{BAM}=180^0\\\widehat{ABN}-\widehat{BAM}=40^0\end{matrix}\right.\)(trong cùng phía)

\(\Rightarrow\widehat{BAM}=\left(180^0-40^0\right):2=70^0\)