Answer:
42º
Step-by-step explanation:
The angle on a straight line is always equal to 180º.
So here we know that angles AEB, BEC and CED add up to 180º. Now we simply have to rearrange to find angles AEB, seeing as we know all the others.
180 - (BEC + CED) = AEB
180 - (48º + 90º)
= 180 - 138º
= 42º
