Question

which pair of undefined terms is used to define a ray? line and plane plane and line segment point and line segment point and line

Explanation:

To determine the pair of undefined terms used to define a ray, we first recall the definitions of undefined terms in geometry (point, line, plane) and the definition of a ray. A ray is defined as a part of a line that starts at a point (the endpoint) and extends infinitely in one direction. So, we need to identify which pair includes the terms necessary for this definition.

• A "line" is an undefined term that extends infinitely in both directions. A "point" is an undefined term representing a location. A ray is formed by taking a point (as the endpoint) on a line and considering the part of the line that extends infinitely from that point in one direction.
• The other options: "line and plane" – a plane is a flat surface, and it's not needed to define a ray. "plane and line segment" – a plane is irrelevant, and a line segment is a defined term (with two endpoints), not used to define a ray. "point and line segment" – a line segment is a defined term and not part of the ray's definition (a ray is infinite, a line segment is finite).

So the correct pair is point and line.

Answer:

D. point and line