if BC = EC, then angle CEB and EBC must be equal as well.
the exterior angle of a triangle is always the some of the other two angles in that triangle.
following this, we can also conclude that angle EBC is simply 138 / 2 = 69.
now we can solve angle ABE, which is just 180 - 69 = 111, because those two angles are on the same straight angle.
hope this helped! sorry if my explanations weren't too clear. please let me know if you are confused about anything i did
if BC = EC, then angle CEB and EBC must be equal as well.
the exterior angle of a triangle is always the some of the other two angles in that triangle.
following this, we can also conclude that angle EBC is simply 138 / 2 = 69.
now we can solve angle ABE, which is just 180 - 69 = 111, because those two angles are on the same straight angle.
hope this helped! sorry if my explanations weren't too clear. please let me know if you are confused about anything i did