Question

which is defined using the undefined terms point and line?
ray
parallel lines
circle
angle

Explanation:

• A ray is defined as a part of a line that has one endpoint (a point) and extends infinitely in one direction. It uses the undefined terms point and line.
• Parallel lines are defined based on the relationship between two lines (they never intersect) and don't directly use the basic definition from just point and line in the same fundamental way as a ray.
• A circle is defined using a center (a point) and a radius (a length, which is related to the concept of distance between points on the line - like from the center to a point on the circle), but its definition is more complex than just a simple combination of point and line as in the case of a ray.
• An angle is defined using two rays (which themselves are based on point and line) sharing a common endpoint, but it is a more compound geometric figure compared to a ray.

Answer:

ray