a) Ta có: c⊥MN,d⊥MN
=> c//d(từ vuông góc đến song song)
b) Ta có: c//d
\(\Rightarrow\widehat{H_1}=\widehat{K_2}=48^0\)(đồng vị)
Ta có: \(\widehat{H_1}+\widehat{H_2}=180^0\)(kề bù)
\(\Rightarrow\widehat{H_2}=180^0-48^0=132^0\)
Ta có: c//d
\(\Rightarrow\widehat{K_1}=\widehat{H_2}=132^0\)(so le trong)
Ta có: \(\widehat{K_2}=\widehat{K_3}=48^0\)(đối đỉnh)