Terms Of A Circle In A Nutshell

Circle: A circle is a closed curve where all points on the curve are equidistant from a fixed point called the center of the circle. The distance from the center to any point on the circle is called the radius.

Diameter: The diameter of a circle is a line segment that passes through the center and has both endpoints on the circle. It is twice the length of the radius.

Chord: A chord is a line segment that connects any two points on the circumference of the circle.

Tangent: A tangent is a line that intersects the circle at exactly one point. It is perpendicular to the radius at the point of intersection.

Secant: A secant is a line that intersects the circle at two distinct points.

Central angle: A central angle is an angle whose vertex is at the center of the circle, and its rays extend to the endpoints of an arc on the circle.

Inscribed angle: An inscribed angle is an angle formed by two chords in a circle with its vertex on the circle. The intercepted arc by the angle is double the measure of the angle.

Arc: An arc is a part of the circumference of a circle. It is named using three points: the starting point, the ending point, and any point on the arc.

Arc length: The arc length is the measure of the portion of the circumference of a circle that corresponds to a given arc. It is proportional to the central angle subtended by the arc.

Sector: A sector is the region bounded by two radii and the corresponding arc.

Congruent arcs: Two arcs are congruent if they have the same measure.