Question

which defines a circle?○ two rays with a common endpoint○ a piece of a line with two endpoints○ a piece of a line with one endpoint○ all coplanar points equidistant from a given point

Explanation:

• "Two rays with a common endpoint" defines an angle, not a circle.
• "A piece of a line with two endpoints" defines a line segment, not a circle.
• "A piece of a line with one endpoint" defines a ray, not a circle.
• A circle is the set of all points in a single plane (coplanar) that are the same distance (equidistant) from a fixed central point.

Answer:

D. all coplanar points equidistant from a given point