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, we recall the definition: two lines (or line segments, rays) are parallel if they lie in the same plane and never intersect, and are always the same distance apart. The undefined terms in geometry are point, line, and plane. To define parallel lines, we need to consider lines within a plane (since parallel lines must be coplanar) and the lines themselves. So the pair of undefined terms used is plane and line.

• Analyzing "point and line": A point and a line alone don't capture the coplanar and non - intersecting nature of parallel lines. A point is just a location, and a line alone doesn't imply the relationship with another line in a plane for parallelism.
• Analyzing "point and ray": A ray is a defined term (a part of a line with a fixed starting point and extending infinitely in one direction), and a point with a ray can't define parallel lines as parallel lines are about the relationship between two lines (or line - like objects) in a plane.
• Analyzing "ray and line": A ray is a defined term, and using a ray (defined) and a line (undefined) doesn't fit the requirement of using only undefined terms to define parallel lines.

Answer:

B. plane and line