Answer:
60°
Step-by-step explanation:
Since, x and 2x are supplementary angles.
[tex] \therefore \: x + 2x = 180 \degree \\ \\ \therefore \: 3x = 180 \degree \\ \\ \therefore \: x = \frac{180 \degree}{3} \\ \\ \huge \red{ \boxed{\therefore \: x = 60 \degree}}[/tex]