A line segment extending from the center of a circle or sphere to a point on the circle or sphere.

A line segment extending from the center of a circle or sphere to a point on the circle or sphere.

• A. Radius
• B. Diameter
• C. Chord
• D. Secant

Answer: (A)

The main idea here is radius. A radius is a line segment from the center of a circle or sphere to a point on its edge (for a sphere, to the surface). It measures the distance from the center to the boundary, and all radii of a given circle have the same length. A diameter is a special case that goes through the center and has endpoints on the circle, effectively two radii back-to-back. A chord is any segment with endpoints on the circle that doesn’t have to pass through the center. A secant is a line that intersects the circle at two points, not a segment from the center to the edge. So the described segment is a radius.

The main idea here is radius. A radius is a line segment from the center of a circle or sphere to a point on its edge (for a sphere, to the surface). It measures the distance from the center to the boundary, and all radii of a given circle have the same length. A diameter is a special case that goes through the center and has endpoints on the circle, effectively two radii back-to-back. A chord is any segment with endpoints on the circle that doesn’t have to pass through the center. A secant is a line that intersects the circle at two points, not a segment from the center to the edge. So the described segment is a radius.