Question

the undefined terms line and plane are needed to precisely define which mathematical term? line segment perpendicular lines parallel lines ray

Explanation:

A line - segment is part of a line with two endpoints. Perpendicular lines are defined by the angle they make (90 degrees) and can be defined in a plane using the concept of angles. Parallel lines are lines in a plane that never intersect. A ray is a part of a line that has one endpoint and extends infinitely in one direction. To define parallel lines precisely, we need the concepts of line and plane. In a plane, two lines are parallel if they do not intersect. In 3 - D space (using the concept of a plane), we can also define parallel lines in relation to the plane they lie in or are related to.

Answer:

parallel lines