2. What is the Circle?
A circle is…
The set of all points equidistant from a given point.
The point from which all the points on a circle are equidistant is called the center
of circle.
3. Radius, Diameter, and Circumference
The Radius is the distance from the center to the edge.
The Diameter starts at one side of the circle, goes through the center and
ends on the other side.
The Circumference is the distance around the edge of the circle.
4. Lines
Chord A segment whose endpoints
are on circle
Center The point from which all
points on a circle are equidistant
Diameter A chord that intersects
with the center of a center
Tangent A line that "just touches"
the circle as it passes
Arc Two endpoints on a circle and
all of the points on the circle between
those two endpoindts/Part of the
circumference
5. Slices
Sectors A region inside a circle
bounded by a central angle and the
minor arc whose endpoints intersect
with the rays that compose the central
angle
Segment The slice made by a chord
7. Another terms
Central Angle An angle whose vertex is the center of a circle
Circumscribed Polygon A polygon whose segments are tangent to a circle
Concentric Circles Circles that share a center
Equidistant The same distance. Objects can be equidistant from one
another
Inscribed Polygon A polygon whose vertices intersect with a circle
Major Arc An arc greater than 180 degrees
Minor Arc An arc less than 180 degrees
Point of Tangency The point of intersection between a circle and its
tangent line or tangent segment
Secant Line A line that intersects with a circle at two points
Tangent Segment A segment with one endpoint at the point of tangency
of a circle and the other endpoint of the tangent line
