Question

which angles are adjacent to each other?

Explanation:

Step1: Recall adjacent - angle definition

Adjacent angles share a common vertex and a common side, and have no interior points in common.

Step2: Analyze each option

• For $\angle AEC$ and $\angle DEA$, they do not share a common side.
• For $\angle DEC$ and $\angle DEA$, they share a common vertex $E$ and a common side $\overrightarrow{DE}$, and have no interior - points in common.
• For $\angle DEB$ and $\angle DEC$, they do not share a common side.
• For $\angle DEB$ and $\angle AEC$, they do not share a common side.

Answer:

$\angle DEC$ and $\angle DEA$