Respuesta :
Answer:
20
Step-by-step explanation:
We know that a triangle's angles must add up to 180 which means that
100+40+2x=180
solve for x
140+2x=180
2x=40
x=20
X in this problem equals 2. This is so because all angles in a triangle add up to equal 180°. You can use that fact to find that the missing angle should equal 40°. You can take that info and divide 40 by 20 which gives you 2. Hope this helps.