Answer:
43°.
Step-by-step explanation:
To find the measures of the other two angles, we will need to use various angle properties.
We can use the Supplementary Angles formula to find the adjacent angle to the angle that measures 123°.
180 - 123 = 57°. This is the measure of the first angle.
Now, to find the measure of the second angle, we know that these are vertical angles meaning they are congruent. Therefore, the measure of the angle is 80°.
To find 'x', we will simply need to subtract from 180:
180 - 80 - 57 = 43°.
