Answer:
120°
Step-by-step explanation:
Let the angle be x then twice it's supplement is 2(180 - x)
Equating the two gives
2(180 - x) = x ← distribute the parenthesis on the left side
360 - 2x = x ( subtract x from both sides )
360 - 3x = 0 ( subtract 360 from both sides )
- 3x = - 360 ( divide both sides by - 3 )
x = 120
The angle is x = 120°
