Question

urgent!!!!!!!!!!!!!!!​

Answer 1

Răspuns:

ΔADC - dreptunghic isoscel ⇒ ∡ACD = ∡DAC = 45°

ΔABO -  isoscel ⇒∡DAB=∡ABO

BE - bisectoare ⇒∡ABO =∡CBE

⇒∡DAB=∡ABO=∡CBE

ΔADB - dreptunghic in D ⇒∡DAB+∡ABO+∡CBE = 90°

⇒3·∡DAB=90°

⇒∡DAB=∡ABO=∡CBE = 30°

⇒∡BAC=∡DAC+∡DAB = 45°+30° = 75°

∡ABC = 2·∡ABO = 60°

deci: in ΔABC: ∡A=75°, ∡B = 60°, ∡C = 45°

∡BOD = 90°-∡CBE = 90°-30° = 60°

∡BOD = 60°