Concurrent lines are three or more lines that intersect at a single point in a plane. This point of intersection is known as the point of concurrency. In geometry, concurrent lines can be found in various shapes and configurations, such as triangles and quadrilaterals. One common example of concurrent lines is the medians of a triangle. The three medians, which connect each vertex to the midpoint of the opposite side, meet at a point called the centroid. This point serves as the center of mass for the triangle and is a key concept in both geometry and physics.