Assessment and Learning in Knowledge Spaces (ALEKS) Practice Exam

What geometric figure is formed when two radii of a circle create a central angle?

1. Sector

2. Chord

3. Quadrilateral

4. Ellipse

The correct answer is: Sector

The figure formed when two radii of a circle create a central angle is called a sector. A sector is defined as the region of a circle bounded by two radii and the arc that lies between them. This area resembles a ‘slice’ of the circle, where the central angle corresponds to the angle formed by the two radii at the center of the circle. The other options do not represent the correct concept. A chord is a line segment whose endpoints lie on the circle, but it does not define an area or sector. A quadrilateral is a polygon with four sides and is not specifically related to the context of a circle and its angles. An ellipse refers to a different type of geometric figure that is not relevant in this instance of circle geometry. Thus, the understanding that the sector is the area created by the two radii forming a central angle is a key concept in the study of circle geometry.