Answer:
40
Step-by-step explanation:
2x+100=180
-100 -100
2x =80
/2 /2
x =40
x = 34
The 3 labeled angles create a straight line, so that means they will add up to 180°.
(x + 12) + 100 + x = 180
2x + 112 = 180
Subtract 112 from both sides.
2x = 68
Divide both sides by 2.
