Question

drag the yellow dot until $overleftrightarrow{ac}$ and $overleftrightarrow{df}$ are exactly parallel. afterwards, use the protractor to measure $angle cbg$ and $angle feb$. make sure the angle measurements are consistent with $overleftrightarrow{ac}$ and $overleftrightarrow{df}$. move the line using the yellow dot. measure the angles with the protractor. you may shift or zoom the canvas using your mouse.

Explanation:

Step1: Recall parallel - line property

When $\overleftrightarrow{AC}$ and $\overleftrightarrow{DF}$ are parallel, $\angle CBG$ and $\angle FEB$ are corresponding angles and are equal.

Step2: Use protractor

Physically use a protractor to measure $\angle CBG$ and $\angle FEB$ on the given diagram. Place the center of the protractor at point $B$ to measure $\angle CBG$ and at point $E$ to measure $\angle FEB$.

Answer:

The measures of $\angle CBG$ and $\angle FEB$ are equal when $\overleftrightarrow{AC}$ and $\overleftrightarrow{DF}$ are parallel. The actual angle - measure values depend on the measurement using the protractor.