AOB si BOC SUNT ADIACENTE COMPLEMENTARE
DECI ASTA INSEAMNA CA ELE SE INTALNESC IN ACELASI PUNCT SI AU SUMA DE 90°
AOB+BOC=90°
m(AOB)=3x+20°
m(BOC)=2x+10°
OD bis AOB
OE bis COB
a)m(AOB)=
m(BOC)=
AOB+BOC=90
3x+20°+2x+10°=90°
5x=90°-30°=60°
x=60°:5
x=12°
m(AOB)=12°×3+20°=36°+20°=56°
m(BOC)12°×2+10°=24°+10°=34°
56°+34°=90°
b) m(DOE)=90°
56°+35°+m(DOE)=180°
90°+m(DOE)=180°
m(DOE)=180°-90°=90°
c)OF semidreapta opusa OE
m(DOF)=
m(AOB)+m(BOC)+m(DOE)+m(DOF)=360°
180°+m(DOF)=360°> m(DOF)=180°
