Geometry: Unit 10 Circles- Tangents, Chords, Arcs, Angles

A set of all points a given distance (radius) from a given point, called the center

A segment with its endpoints on the circle

The longest chord of a circle that always passes through the center

A continuous portion of between two points on the circle

An arc that is half a circle, the arc’s endpoints are at the diameter, arc measure is 180°

An arc that is smaller than semi-circle, the arc measure is less than 180°

An arc that is larger than a semi-circle, the arc measure is greater than 180°

A line that intersects the circle at exactly two points

A line that intersects the circle at exactly one point or touches the circle at 1 point

An area of circle bounded by two radii and an arc

A tangent to a circle is perpendicular to the radius drawn to the point of tangency.

Tangent segments to a circle from a point outside the circle are congruent.

An angle made up of two radius on the circle’s circumference with its vertex at the circle’s center. The measure of the central angle is equal to the measure of its arc.

An angle made up of two chords with its vertex on the circle’s circumference

If two chords in a circle are congruent, then they determine two central angles that are congruent.

If two chords in a circle are congruent, then their intercepted angles are congruent

The perpendicular from the center of a circle to a chord is the bisector of the chord

Two congruent chords in a circle are equidistant from the center of the circle

The perpendicular bisector of a chord passes through the center of a circle

The measure an inscribed angle is half the measure of its intercepted arc

The measure of an angle formed by a chord and a tangent is half the measure of its intercepted arc