Question

select the lines that are skew to $overleftrightarrow{ab}$ (more than one correct answer)
a $overleftrightarrow{ef}$
b $overleftrightarrow{eh}$
c $overleftrightarrow{cg}$
d $overleftrightarrow{ad}$

Explanation:

Step1: Recall definition of skew lines

Skew lines are non - parallel and non - intersecting lines in 3 - D space.

Step2: Analyze each option

• For $\overleftrightarrow{EF}$: $\overleftrightarrow{EF}$ is parallel to $\overleftrightarrow{AB}$, so it is not skew.
• For $\overleftrightarrow{EH}$: $\overleftrightarrow{EH}$ and $\overleftrightarrow{AB}$ are in different planes, non - parallel and non - intersecting.
• For $\overleftrightarrow{CG}$: $\overleftrightarrow{CG}$ and $\overleftrightarrow{AB}$ are in different planes, non - parallel and non - intersecting.
• For $\overleftrightarrow{AD}$: $\overleftrightarrow{AD}$ intersects $\overleftrightarrow{AB}$ at point $A$, so it is not skew.

Answer:

B. $\overleftrightarrow{EH}$, C. $\overleftrightarrow{CG}$