от Xixibg » 30 Ное 2011, 09:26
[tex]\alpha =2x ; \beta =3x ; \gamma =7x[/tex]
[tex]\alpha +\beta +\gamma =2x+3x+7x=180^\circ[/tex]
[tex]12x=180^\circ[/tex]
[tex]x=\frac{180}{12}=15[/tex]
[tex]\alpha =2x =2.15=30^\circ[/tex]
[tex]\beta =3x =3.15=45^\circ[/tex]
[tex]\gamma =7x=7.15=105^\circ[/tex]