Question

1. (overleftrightarrow{fh}) and (overleftrightarrow{ce}) are parallel lines.
2. which angles are supplementary angles?
3. (angle fgi) and (angle hgi) (angle fgi) and (angle edh) (angle fgi) and (angle hgd) (angle fgi) and (angle cdg)

Explanation:

Step1: Recall supplementary - angle definition

Two angles are supplementary if their sum is 180 degrees. Adjacent angles that form a straight - line are supplementary.

Step2: Analyze angle relationships

$\angle FGI$ and $\angle HGI$ form a straight - line at point $G$. So, $\angle FGI+\angle HGI = 180^{\circ}$.

Answer:

$\angle FGI$ and $\angle HGI$