Question

in the square pyramid shown below, which lines are skew? fg and fi gj and gh ij and gh gj and fi

Explanation:

Step1: Recall skew - line definition

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

Step2: Analyze each option

• $\overrightarrow{FG}$ and $\overrightarrow{FI}$ intersect at point $F$, so they are not skew.
• $\overrightarrow{GJ}$ and $\overrightarrow{GH}$ are in the same face (the base square), so they are not skew.
• $\overrightarrow{IJ}$ and $\overrightarrow{GH}$ are parallel as they are opposite sides of the base square, so they are not skew.
• $\overrightarrow{GJ}$ and $\overrightarrow{FI}$ are non - parallel and do not intersect. They are in different planes and are skew.

Answer:

$\overrightarrow{GJ}$ and $\overrightarrow{FI}$