Răspuns :
Stim ca m(A) +m(B) =180
8m(B) +m(B) =180
m(B) =180/9 = 20 grade
m(A) =8x20 =160 grade
8m(B) +m(B) =180
m(B) =180/9 = 20 grade
m(A) =8x20 =160 grade
Obs. Într-un romb, unghiurile alăturate sunt suplementare.
m(∡A) + m(∡B) = 180° dar m(∡A) = 8 × m(∡B)
8 × m(∡B) + m(∡B) = 180°
9 × m(∡B) = 180°
m(∡B) = 180° : 9
m(∡B) = 20°
m(∡A) + m(∡B) = 180° dar m(∡B) = 20°
m(∡A) + 20° = 180°
m(∡A) = 180° - 20°
m(∡A) = 160°
m(∡A) + m(∡B) = 180° dar m(∡A) = 8 × m(∡B)
8 × m(∡B) + m(∡B) = 180°
9 × m(∡B) = 180°
m(∡B) = 180° : 9
m(∡B) = 20°
m(∡A) + m(∡B) = 180° dar m(∡B) = 20°
m(∡A) + 20° = 180°
m(∡A) = 180° - 20°
m(∡A) = 160°