Answer:
57
Step-by-step explanation:
The answer is 57 because if angle 4 is 123 and angle 4 is equal to angle 3 then angle 3 is also 123. Then you would subtract 180 - 123 which is equal to 57.
TKL is 57°
since angle 3 is equal to angle 4 and angle 4 equals 123°, then angle 3 is 123°
subtract 123 from 180 then you get 57
