What do you call the line segment that runs from the center of the circle to a point on the circle?

The line segment that runs from the center of the circle to a point on the circle is defined as the radius. By definition, the radius represents the distance from the center of the circle out to its circumference, and it is a fundamental aspect of circular geometry.

The radius is crucial for various calculations, such as finding the area of a circle or determining its circumference, as these formulas rely on the length of the radius. Furthermore, every circle has an infinite number of radii, as any line segment from the center to the circumference qualifies as a radius, illustrating the concept more deeply.

In contrast, other terms related to a circle carry different meanings. The diameter refers to a line segment that passes through the center of the circle and touches both sides of the circumference, making it twice the length of the radius. A chord is any line segment that connects two points on the circumference, but it does not necessarily pass through the center. A line segment is a general term that can describe any portion of a line with endpoints, but it lacks the specific context provided by the definitions of radius, diameter, or chord in relation to a circle.