Question

the movement of the progress bar may be uneven because questions can be worth more or less (including zero) depending on your answer. identify a set of parallel and a set of perpendicular lines in this image. a b c d e f g h
○ $overleftrightarrow{bf} parallel overleftrightarrow{cg}$, $overleftrightarrow{bf} perp overleftrightarrow{cg}$
○ $overleftrightarrow{ad} parallel overleftrightarrow{eh}$, $overleftrightarrow{eh} perp overleftrightarrow{bf}$
○ $overleftrightarrow{ad} parallel overleftrightarrow{eh}$, $overleftrightarrow{bf} perp overleftrightarrow{cg}$
○ $overleftrightarrow{bf} parallel overleftrightarrow{cg}$, $overleftrightarrow{ad} perp overleftrightarrow{eh}$

Explanation:

Parallel lines are non-intersecting with same direction; perpendicular lines intersect at 90°. $\overrightarrow{AD}$ and $\overrightarrow{EH}$ are horizontal (parallel). $\overrightarrow{EH}$ (horizontal) and $\overrightarrow{BF}$ (vertical) intersect at 90° (perpendicular).

Answer:

B. $\overrightarrow{AD} \parallel \overrightarrow{EH}$, $\overrightarrow{EH} \perp \overrightarrow{BF}$