Respuesta :

Answer:

80°

Step-by-step explanation:

∠ABC= ∠ABD+∠CBD

as BD bisects ∠ABC, we have

  • ∠ABD=∠CBD
  • 2x+20°= 4x
  • 2x=20°
  • x=10°

∠ABC= 2*4x= 8x= 80°