Question

consider the diagram.
lines a and d are
non - coplanar.
parallel
perpendicular.
skew.

Explanation:

1. Recall the definitions:

• Non - coplanar: Lines that do not lie on the same plane. But line \(a\) and line \(d\) seem to lie on the same plane (the horizontal plane \(N\) or the intersection plane).
• Parallel: Lines in the same plane that never meet and have the same direction. From the diagram, line \(a\) is vertical (down - up) and line \(d\) is horizontal (left - right), so they are not parallel.
• Perpendicular: Lines that intersect at a right angle (90 degrees). The diagram shows a right - angle symbol between line \(a\) and line \(d\), so they intersect at 90 degrees.
• Skew: Lines that are non - coplanar and do not intersect. Since \(a\) and \(d\) intersect, they are not skew.

Answer:

perpendicular.