Question

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

Explanation:

• An angle is defined by two rays (which involve points and lines) but let's analyze each option:
• Angle: Defined as the union of two rays with a common endpoint (a point), but the definition of ray is needed first.
• Circle: Defined as the set of all points equidistant from a given point (center), mainly using the undefined term "point" and the concept of distance, not directly line.
• Parallel lines: Defined as lines in a plane that never meet, but this definition relies on the definition of "line" and the concept of a plane (another undefined term in some systems), but not as direct as ray.
• Ray: A ray is defined as a part of a line that starts at a point (an undefined term) and extends infinitely in one direction along the line (another undefined term). So a ray is directly defined using the undefined terms point and line.

Answer:

D. ray (assuming the options are labeled A: angle, B: circle, C: parallel lines, D: ray)