What is a sector in a circle?

A sector in a circle is indeed defined as the region enclosed by two radii and the arc between them. This portion of the circle resembles a "slice" of pizza, where the pointed tip of the slice is at the center of the circle, and the curved edge is part of the circumference. The two radii act as the sides of the sector, creating a wedge-shaped area.

Understanding the concept of a sector is fundamental in geometry, especially when dealing with problems involving area calculations or angular measurements. In contrast, the other options describe different elements related to circles. For example, a chord connects two points on the circumference but does not create a sector. A complete circle refers to the entire area enclosed by the circumference, and an area outside of a circle describes regions that are not part of the circle itself. These aspects highlight the unique characteristics of a sector, focusing on its definition relating specifically to its formation through radii and an arc.