suma masurilor unghiurilor intr un triunghi este 180°
notam unghiurile cu a,b si c
a+b+c=180
{a,b,c} d.p. {1,3,5}
[tex] \frac{a}{1} = \frac{b}{3} = \frac{c}{5} = k[/tex]
k-coeficient de proportionalitate
[tex] \frac{a}{1} = k = > a = 1k[/tex]
[tex] \frac{b}{3 } = k = > b = 3k[/tex]
[tex] \frac{c}{5} = k = > c = 5k[/tex]
a+b+c=180
k+3k+5k=180
9k=180
k=180:9
k=20
a=1k=>a=20°
b=3k=>b=3×20=>b=60°
c=5k=>c=5×20=>c=100°
