Geometry A Unit 6 Flashcards
Center of an Arc
The center of the circle that contains the arc.
Center of a circle
The point in the plane equidistant from all points of the circle.
Central angle
An angle with its vertex at the center of a circle.
chord
A segment with end points on the circle.
circle
The set of all points in a plane that are at a given distance from a given point in the plane.
circumscribed polygom
A polygon with each side tangent to the circle contained within.
common external tangent
A tangent to two coplanar circles such that a segment connecting the centers of the circles does not intersect the tangent.
common internal tangent
tangent to two coplanar circles such that a segment connecting the centers of the circles intersects the tangent.
concentric angles
Two or more circles that lie in the same plane and have the same center.
congruent circles
Circles that have equal radii.
diameter
A chord of a circle that contains the center of the circle.
inscribed angle
The intersection of a sphere and a plane that passes through the center of the sphere.
inscribed angle
An angle with vertex that is a point of an arc other than the end points and with sides that pass through the end points of the arc.
intercepted arc
The arc with end points that are points of the sides of the angle and including all points on the arc in the interior of the angle.
major arc
The union of two points of a circle, not the end points of a diameter; and all points of the circle that lie in the exterior of the central angle with sides that contain the two points.
minor arc
The union of two points of the circle, not the ends of a diameter; and all points of the circle that lie in the interior of the central angle with sides that contain the two points.
midpoint of an arc
A point x on the arc ABC such that m AXC = m XBC.
radius
A segment joining the center of a circle to a point of the circle.
secant
A line that contains a chord of a circle.
secant ray
A ray that lies on a secant line and contains both points of intersection with the circle.
semi-circe
The union of the endpoints of a diameter of a circle and all points of the circle lying on the same side of the diameter.
small circle
The intersection of a sphere and a plane that does not pass through the center of the sphere.
sphere
The set of all points at a given distance from a given point.
Tangent circles
Two coplanar circles that are tangent to the same line at the same point.
tangent line
A line that lies in the plane of the circle and intersects the circle in exactly one point.
tangent ray
A ray that lies on a tangent line and contains the point of tangency.
