Question

which pair of undefined terms is used to define the term parallel lines?
○ point and line
○ plane and line
○ point and ray
○ ray and line

Explanation:

To define parallel lines (lines in a plane that never meet and are equidistant), we need to consider the undefined terms. Undefined terms in geometry are point, line, and plane. Parallel lines are defined as lines in the same plane (plane) that do not intersect, and the concept of a line is fundamental here. A plane provides the context (since parallel lines are coplanar), and a line is the object. Point and line: A point is a location, but parallel lines' definition relies more on the plane and line relationship. Point and ray: Ray is a defined term (part of a line), so not suitable. Ray and line: Ray is defined, so incorrect. So the pair is plane and line.

Answer:

B. plane and line