Hello!
Angles AEB and BEC are examples of supplementary angles. Supplementary angles are two angles whose measures add to a sum of 180 degrees. This can be represented using the following formula:
A1 + A2 = 180
In this case, the formula can be rewritten to state the following:
∠AEB + ∠BEC = 180
Insert any values given in the problem above:
∠AEB + 127 = 180
Now subtract 127 from both sides of the equation:
∠AEB = 53
We have now proven that ∠AEB has a measure of 53 degrees.
I hope this helps!