A chord of a circle of a circle divides its circular region into two parts. Each part is called__________.

Each part created by a chord in a circle is called a segment. A segment is a region bounded by a chord and the arc that subtends that chord. When a chord divides a circle, it creates two distinct segments, one on each side of the chord. The nature of these segments can vary depending on the position of the chord within the circle.

The upper segment is the larger area above the chord, commonly referred to as the "major segment," while the lower segment is the smaller area below the chord, known as the "minor segment." Understanding segments is crucial in geometry, especially when dealing with circle-related problems such as areas, circumferences, and various properties of chords and arcs. Each segment has unique properties and calculations associated with it, particularly when it comes to measuring angles and determining areas.