Answer: The two angles add up to 180 so they are supplementary angles.
The sum of their measures is 180 degrees.
Explanation:
Plug in given value for x.
x=20
(3x+50)=
(60+50)=110
110
(4x-10)=
80-10=70
70
There are several true things about these angles you can find from this information but I think you are looking for the answer at top.