A chord in a circle is a straight line segment that connects any two points on the circumference (edge) of the circle. It lies entirely inside the circle except at its endpoints, which are on the circle itself

. A special type of chord is the diameter, which is the longest chord possible in a circle because it passes through the center of the circle, dividing it into two equal halves

. Key points about chords in a circle include:

• Any line segment joining two points on the circle is a chord.
• The diameter is a chord that passes through the center and is the longest chord.
• The perpendicular drawn from the center of the circle to a chord bisects the chord (splits it into two equal parts)

• Equal chords are equidistant from the center of the circle

In summary, a chord is a fundamental geometric element of a circle defined as a line segment with endpoints on the circle's circumference, with the diameter being the longest and most special chord