What is the measure of angle 1?

Answer:
C
Step-by-step explanation:
Let find the measure of the angle supplementary to Angle 1.
[tex] \frac{123 + 84}{2} = 103.5[/tex]
Angle 1 is supplementary to that angle so
[tex]103.5 + x = 180[/tex]
[tex]x = 76.5[/tex]