Assessment and Learning in Knowledge Spaces (ALEKS) Practice Exam

What do you call the distance across the circle, passing through the center?

1. Diameter

2. Radius

3. Chord

4. Arc

The correct answer is: Diameter

The distance across a circle that passes through its center is referred to as the diameter. The diameter is the longest straight line that can be drawn within the circle, connecting two points on its circumference and passing directly through the center. In contrast, the radius is the distance from the center of the circle to any point on its circumference, which is essentially half of the diameter. A chord is any straight line segment whose endpoints lie on the circumference of the circle, but it does not have to pass through the center, and an arc is a portion of the circumference of the circle. Understanding these definitions clarifies why the diameter is specifically defined as the distance that crosses the circle through its center.