how do i determine the value of x?

Answer:
x=65
Step-by-step explanation:
When angles are across from eachother like that their values are the same.
so you set them equal to eachother.
120 = 2x - 10
130 = 2x add 10 to both sides
130/2 = 2x/ 2 divide both sides by 2
65 = x
Answer:
Considering that you are trying to find 'x' it is best to make an equation!
Step-by-step explanation:
To find 'x' you must first make an equation!
Since both are the same lengths, you can put these two equal to each other!
(2x - 10)° = 120°
Then solve like normal!
2x - 10° = 120°
+10° = +10°
--------------------
2x = 130°
(Then divide both sides by 2)
2x/2 = 130/2
x = 65°