Question

in the cube shown below, which lines are intersecting? select all that apply.

Explanation:

Step1: Recall intersecting lines definition

Intersecting lines share a common point.

Step2: Analyze $\overleftrightarrow{DE}$ and $\overleftrightarrow{EI}$

They meet at point E.

Step3: Analyze $\overleftrightarrow{BC}$ and $\overleftrightarrow{CG}$

They meet at point C.

Step4: Analyze $\overleftrightarrow{CG}$ and $\overleftrightarrow{FG}$

They meet at point G.

Step5: Analyze $\overleftrightarrow{CD}$ and $\overleftrightarrow{GH}$

In 3 - D space of cube, they do not intersect.

Answer:

$\overleftrightarrow{DE}$ and $\overleftrightarrow{EI}$, $\overleftrightarrow{BC}$ and $\overleftrightarrow{CG}$, $\overleftrightarrow{CG}$ and $\overleftrightarrow{FG}$