Respuesta :

Answer:

21°, 42°, 117°

Step-by-step explanation:

arc represents the central angle, so angle at the circumference is the half of central angle

  • b=84°/2= 42°
  • a=42°/2= 21°
  • a+b=180°-c ⇒ c= 180°- (42°+21°)= 180°- 63°= 117°