Vẽ \(\widehat {ABC} = {56^o}\). Vẽ \(\widehat {ABC'}\) kề bù với \(\widehat {ABC}\). Sau đó vẽ tiếp \(\widehat {C'BA'}\) kề bù với \(\widehat {ABC'}\). Tính số đo \(\widehat {C'BA'}\).

\(\widehat {z'At'}\)

\(\widehat {z'At}\)     

\(\widehat {zAt'}\) \(\)

\(\widehat {zAt}\)

$30^\circ$

$120^\circ$

$90^\circ$

$60^\circ$

$\widehat {x'Oy} = 135^\circ $                   

$\widehat {x'Oy'} = 45^\circ $

$\widehat {xOy'} = 135^\circ $

$\widehat {x'Oy'} = 135^\circ $

\(\widehat {zOt} = \widehat {z'Ot'} = 72^\circ \)

\(\widehat {zOt} = \widehat {z'Ot'} = 30^\circ \)

\(\widehat {zOt} = \widehat {z'Ot'} = 36^\circ \)

\(\widehat {zOt} = 72^\circ ;\,\widehat {z'Ot'} = 36^\circ \)

\({\widehat O_2} = {165^o};\,{\widehat O_3} = {15^o};\,\,{\widehat O_4} = {165^o}\,\,\)              

\({\widehat O_2} = {165^o};\,{\widehat O_3} = {15^o};\,\,{\widehat O_4} = {15^o}\,\,\)              

\({\widehat O_2} = {15^o};\,{\widehat O_3} = {15^o};\,\,{\widehat O_4} = {165^o}\,\,\)   

\({\widehat O_2} = {15^o};\,{\widehat O_3} = {165^o};\,\,{\widehat O_4} = {15^o}\,\,\)

\(\widehat {xOy'}\,\,;\,\,\widehat {x'Oy'}\)                

\(\widehat {xOy}\,\,;\,\,\widehat {x'Oy'}\)

\(\widehat {xOy'}\,\,;\,\,\widehat {x'Oy}\)  

\(\widehat {xOy'}\,\,;\,\,\widehat {xOy}\)