Respuesta :

AyaanR
x + x + 12 + x - 9 = 180
3x = 180 - 12 + 9
3x = 168 + 9
3x = 177
x = 59 degrees

Angle 1 = 59 degrees
Angle 2 = 59 + 12 = 71 degrees
Angle 3 = 59 - 9 = 50 degrees
Yosola

Answer:

x+(x+12)+(x-9)=180

3x+12-9=180

3x=180-3

3x=177

x=177/3

x=59

Each angle is 59°, 71° and 500°