Respuesta :

All traingles equal 180 degrees.
Do 40 + x + x + 20 = 180
60 + 2x = 180
2x = 120
/2      /2
x = 60
x+(x+20)+40=180
2x + 60 = 180
subtract 60 from both sides
2x = 120
divide both sides by 2
x = 60