Which statement correctly defines the diameter of a circle?

Which statement correctly defines the diameter of a circle?

• A. The distance around the circle
• B. The distance from the center to the circle
• C. Length from edge to edge across the circle
• D. The area of the circle

Answer: (C)

A diameter is a straight line segment that passes through the center of the circle and has endpoints on the circle. Because it goes through the center, it is the longest possible distance between two points on the circle and its length is twice the radius. The statement describing the length from edge to edge across the circle captures exactly this idea. The other concepts refer to different properties: the distance around the circle is the circumference, the distance from the center to the circle is the radius, and the area is pi times the radius squared.

A diameter is a straight line segment that passes through the center of the circle and has endpoints on the circle. Because it goes through the center, it is the longest possible distance between two points on the circle and its length is twice the radius. The statement describing the length from edge to edge across the circle captures exactly this idea. The other concepts refer to different properties: the distance around the circle is the circumference, the distance from the center to the circle is the radius, and the area is pi times the radius squared.