# McDougal Littel Vocab.

The set of all points in a plane that are equidistant from a given point circle
A give point that is equidistant to all the points in a plane center of circle
The distance from the center of a circle to a point on the circle. A segment whose endpoints are the center of the circle and a point on the circle. radius of circle
Two circles that have the same radius. congruent circles
A chord that passes through the center of the circle. The distance across a circle, through its center. diameter of circle
A segment whose endpoints are points on the circle. chord of a circle
Circle that intersect in one point. tangent circles
Circles that have a common center. concentric circles
A line or segment that is tangent to two circles. A common internal tangent intersects the segment that joins the centers of the two circles. A common external tangent does not intersect the segment that joins the centers of the two circles. common tangent
All points of the plane that are inside a circle. interior of a circle
All points of the plane that are outside a circle. exterior of a circle
A line that intersects a circle in exactly one point. point of tangency
An angle whose vertex is the center of a circle. central angle of a circle
Part of a circle measures less than 180 degrees. minor arc
Part of a circle that measures between 180 degrees and 360 degrees. major arc and its measure
An arc whose endpoints are the endpoints of a diameter of the circle. semicircle
Two arcs of the same circle or of congruent circles that have the same measure. congruent arcs
An angles whose vertex in on a circle and whose sides contain chords of the circle. inscribed angle
The arc that lies in the interior of an inscribed angle and has endpoints on the angle. intercepted arc
A polygon whose vertices all lie on a circle. inscribed polygon
A circle with an inscribed polygon. circumscribed circle
A segment that is tangent to a circle at an endpoint. tangent segment
A segment that intersects a circle in two points, with one point as an endpoint of the segment. secant segment
The part of a segment that is not inside the circle. external segment
The set of all points that satisfy a given condition or a set of given conditions. locus
A segment that intersects a circle in two points, with one point as an endpoint of the segment. secant tangent