Answer:
lower Right.
Step-by-step explanation:
Remark
The two angles share the same side of vertically opposite angles. That makes them supplementary which means the two angles add to 180 degrees.
Equation
4x + 8x + 12 = 180 Combine like terms on the left
Solution
- 12x + 12 = 180 Subtract 12 from both sides
- 12x = 180 - 12 Combine
- 12x = 168 Divide by 12
- x = 168/12
- x = 14
