Answer:
130 degrees
Explanation:
I first came up with the equation 30+20+?=180 (I got 180 because every angle in a triangle added up is 180), then added the 30 and 20 to get 50+?=180. I subtracted 50 from both sides and got ?=130. I know that the angle on the inside and the outside are equal because it seems like a reflection, so if the inside angle is 130 the outside angle is 130 degrees too.
Hope this helps you :)