Question

which angle is adjacent to ∠aeb? ∠aec ∠dec ∠ced ∠bed

Explanation:

Step1: Recall adjacent - angle definition

Adjacent angles share a common vertex and a common side, and have no interior - points in common.
For $\angle AEB$, the angle that shares the vertex $E$ and a common side with it is $\angle BED$. $\angle AEB$ and $\angle BED$ have vertex $E$ in common and side $EB$ in common.

Step2: Analyze other options

• $\angle AEC$ does not share a common side with $\angle AEB$.
• $\angle DEC$ does not share a common side with $\angle AEB$.
• $\angle CED$ does not share a common side with $\angle AEB$.

Answer:

$\angle BED$