Question

which angles are congruent to each other? ∠dea and ∠ebj ∠gch and ∠ecf ∠aeb and ∠dea ∠hce and ∠gch

Explanation:

Step1: Recall vertical - angle property

Vertical angles are congruent. When two lines intersect, the pairs of opposite angles formed are vertical angles.

Step2: Identify vertical - angle pairs

In the given figure, when lines intersect, $\angle GCH$ and $\angle ECF$ are vertical angles.

Answer:

$\angle GCH$ and $\angle ECF$