What is a Chord in a Circle?
A line segment that connects two points on a circle. The longest chord is the diameter, which passes through the center of the circle.
In math, a chord is a straight line that connects any two points on the circumference of a circle. Every chord lies entirely inside the circle.
The diameter is the longest chord in a circle because it passes through the center, dividing the circle into two equal halves.
Chords help us explore the shape and structure of circles, especially when we study arcs, angles, and symmetry in geometry. We often use them when solving problems about circular objects like wheels, round tables, or sports fields.
When Do Students Learn About Chords?
Students begin learning about chords as part of circle geometry in middle school.
Grades 6–8 – Introduction to Chords
Students learn what chords are, identify them in circles, and explore their basic properties.
Grades 9+ – Chords in Geometry
Students use chords in circle theorems, solve problems involving secants and tangents, and connect chords to arcs and angles.
