Question

in the triangular pyramid shown below, which lines are intersecting?
de and ef
de and fg
dg and ef
df and eg

Explanation:

Step1: Recall intersecting lines definition

Intersecting lines share a common point.

Step2: Analyze each option

• For $\overleftrightarrow{DE}$ and $\overleftrightarrow{EF}$, they share point $E$.
• $\overleftrightarrow{DE}$ and $\overleftrightarrow{FG}$ are skew - no common point.
• $\overleftrightarrow{DG}$ and $\overleftrightarrow{EF}$ are skew - no common point.
• $\overleftrightarrow{DF}$ and $\overleftrightarrow{EG}$ are skew - no common point.

Answer:

$\overleftrightarrow{DE}$ and $\overleftrightarrow{EF}$