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circle

The set of points in a plane that are equidistant from a given point called the center.

radius

A segment whose endpoints are the center and any point on the circle.

chord

A segment whose endpoints are on the circle.

secant

A line that intersects a circle in two points

tangent

A line in the plane of a circle that intersects the circle in exactly one point.

standard equation of a circle

(x-h)² + (y-k)² = r²

diameter

A chord that contains the center of the circle

minor arc

An arc of a circle that measures more than zero, but less than 180 degrees.

major arc

An arc of a circle that measures greater than 180, but less than 360 degrees.

inscribed angle

An angle whose vertex is on the circle and whose sides contain chords of the circle.