[tex]2m(\hat2)=3m(\hat7) \ \ \ \ (1)
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\hat2\ \c{s}i \ \hat7 \ sunt \ suplementare \Rightarrow m(\hat7) =180^o-m(\hat2) \ \ \ \ (2)[/tex]
[tex]\it (1),\ (2) \Rightarrow 2m(\hat2) = 3(180^o-m(\hat2)) \Rightarrow 2m(\hat2)=3\cdot180^o -3m(\hat2) \Rightarrow
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2m(\hat2)+3m(\hat2) = 540^o \Rightarrow 5m(\hat2) =540^o|_{:5} \Rightarrow m(\hat2) = 108^o[/tex]
[tex]\it \hat2\ \c{s}i \ \hat3 \ sunt \ suplementare \Rightarrow m(\hat3) =180^o-m(\hat2) =180^o-108^o=
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=72^o[/tex]
