Which lines are described as concurrent?

Concurrent lines are defined as multiple lines that intersect at a single point. This means that at least three or more lines meet at one location, which is essential for considering them concurrent. The concept of concurrency is significant in various areas of mathematics and geometry, particularly in discussions about points of intersection and the properties of triangles and other geometric figures.

The other options describe different properties of lines. Lines that never intersect are parallel, forming no common points. Lines that form perpendicular angles refer specifically to the relationship where two lines meet to create a right angle, but they don't necessarily imply that multiple lines meet at a single point. Lines that extend infinitely in one direction describe rays, which again do not relate to the idea of concurrency.