Hello there!
We know a vertical line = 180 degrees
x + 20 + 7x = 180
we can simplify this
20 + 8x = 180
To solve this, we can work backwards.
180 - 20 = 160
8x = 160
160/8 = 20
x = 20 degrees
Hope I helped!
Let me know if you need anything else!
~ Zoe
