Which statement describes the diameter of a circle?

Which statement describes the diameter of a circle?

• A. The distance from the center to any point on the edge.
• B. The distance around the circumference.
• C. The line segment through the center that connects two points on the circle's edge.
• D. The length of a tangent from a point outside the circle.

Answer: (C)

The diameter is the line segment that passes through the center of the circle and connects two points on the circle's edge. Because it goes through the center, it is the longest possible chord in the circle and its length is twice the radius. This makes the diameter a defining measure of the circle’s size. The other ideas describe different concepts: the radius is the distance from the center to the edge; the circumference is the distance around the circle; and a tangent from an external point is a line that touches the circle at only one point.

The diameter is the line segment that passes through the center of the circle and connects two points on the circle's edge. Because it goes through the center, it is the longest possible chord in the circle and its length is twice the radius. This makes the diameter a defining measure of the circle’s size. The other ideas describe different concepts: the radius is the distance from the center to the edge; the circumference is the distance around the circle; and a tangent from an external point is a line that touches the circle at only one point.