Answer:
Supplementary angles
Explanation:
The two angles shown are supplementary. You can see if the 3x+15 were to slide down to the next line, how the 3x+15 and 2x would make up a linear pair. Together they add up to 180°
Not sure if you need it, but to solve for x:
3x+15 + 2x = 180
combine like terms.
5x + 15 = 180
Subtract 15.
5x = 165
divide by 5
x = 33
Then you can find the measures of the angles.
3(33)+15
= 114°
2(33)
=66°