a:
Các cặp góc so le trong là: \(\widehat{M_3};\widehat{N_3}\); \(\widehat{M_4};\widehat{N_4}\)
Các cặp góc đồng vị là: \(\widehat{M_1};\widehat{N_4}\); \(\widehat{M_2};\widehat{N_3}\); \(\widehat{M_3};\widehat{N_1}\); \(\widehat{M_2};\widehat{N_3}\)
b:
Ta có: a//b
=>\(\widehat{M_1}=\widehat{N_4}\)(hai góc đồng vị)
=>\(\widehat{N_4}=56^0\)
Ta có: \(\widehat{N_4}=\widehat{N_2}\)(hai góc đối đỉnh)
mà \(\widehat{N_4}=56^0\)
nên \(\widehat{N_2}=56^0\)
Ta có: \(\widehat{N_4}+\widehat{N_3}=180^0\)(hai góc kề bù)
=>\(\widehat{N_3}=180^0-56^0=124^0\)
Ta có: \(\widehat{N_3}=\widehat{N_1}\)(hai góc đối đỉnh)
mà \(\widehat{N_3}=124^0\)
nên \(\widehat{N_1}=124^0\)
Ta có: \(\widehat{M_1}+\widehat{M_2}=180^0\)(hai góc kề bù)
=>\(\widehat{M_2}=180^0-56^0=124^0\)
Ta có: \(\widehat{M_1}=\widehat{M_4}\)(hai góc đối đỉnh)
mà \(\widehat{M_1}=56^0\)
nên \(\widehat{M_4}=56^0\)
Ta có: \(\widehat{M_2}=\widehat{M_3}\)(hai góc đối đỉnh)
mà \(\widehat{M_2}=124^0\)
nên \(\widehat{M_3}=124^0\)
