What is the definition of a secant line in relation to a circle?

A secant line is defined specifically by its relationship to a circle: it intersects the circle at two distinct points. This characteristic sets it apart from other lines that interact with the circle.

For instance, a tangent line touches the circle at exactly one point and does not extend into the interior of the circle. A line that passes outside the circle without intersecting it cannot be classified as a secant, as it fails to meet the criteria of intersecting the circle at any point. Finally, a line being parallel to a radius signifies that it has a specific directional relationship to the circle but does not provide any information about intersection points with the circle itself.

Thus, the definition of a secant line is anchored in its ability to intersect a circle in two places, making it crucial to understanding how lines and circles interact in geometric contexts.