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.