Question

bd and eg are parallel lines. which angles are vertical angles? ∠gfc and ∠efc ∠gfc and ∠bca ∠gfc and ∠efh ∠gfc and ∠dca

Explanation:

Step1: Recall the definition of vertical angles

Vertical angles are a pair of non - adjacent angles formed by the intersection of two lines. They are opposite each other.

Step2: Analyze each option

• For $\angle GFC$ and $\angle EFC$: These are adjacent angles (they share a common side $FC$), so they are not vertical angles.
• For $\angle GFC$ and $\angle BCA$: These are not formed by the intersection of the same two lines, so they are not vertical angles.
• For $\angle GFC$ and $\angle EFH$: When lines $AG$ and $EH$ intersect at point $F$, $\angle GFC$ and $\angle EFH$ are non - adjacent and opposite each other. By the definition of vertical angles, they are vertical angles.
• For $\angle GFC$ and $\angle DCA$: These are not formed by the intersection of the same two lines, so they are not vertical angles.

Answer:

$\angle GFC$ and $\angle EFH$