6.
[tex]\it Not\breve am\ \widehat{BOD}=x\ \Rightarrow \widehat{AOD}=2x\\ \\ \widehat{BOD}\ \c{s}i\ \widehat{AOD}\ sunt\ suplementare\ \Rightarrow\ x+2x=180^o \Rightarrow 3x=180^o|_{:3} \Rightarrow x=60^o\\ \\ \widehat{AOD}=2x=2\cdot60^o=120^o\\ \\ \widehat{COB}= \widehat{AOD}=120^o\ (opuse\ la\ v\hat arf)[/tex]
7.
Unghiurile formate în jurul unui punct au suma măsurilor egală cu 360°.
[tex]\it \widehat{DOB}=360^o-90^o-21^o=249^o\\ \\ \widehat{AOD}=(249^o-27^o):2=111^o\\ \\ \widehat{AOB}=111^o+27^o=138^o[/tex]
[tex]\it [OE-bisectoare \ pentru\ \widehat{AOB} \Rightarrow \widehat{AOE} =138^o:2=69^o\\ \\ \widehat{DOE} =\widehat{DOA} +\widehat{AOE} =111^o+69^o=180^o \Rightarrow D,\ O,\ E-\ puncte\ coliniare[/tex]
