Question

which angle is vertical to ∠ced?

Explanation:

Step1: Recall vertical - angle definition

Vertical angles are formed when two lines intersect. They are opposite each other.

Step2: Identify intersecting lines

Lines $AB$ and $FI$ intersect at point $E$.

Step3: Determine vertical angle to $\angle CED$

The angle opposite to $\angle CED$ is $\angle HEF$.

Answer:

$\angle HEF$