Circle – All the points in a plane equidistant from a fixed point
Minor Arc – An arc whose measure is less than 180 degrees
Major Arc – An arc whose measure is greater than 180 degrees
Semi-Circle – An arc whose measure is equal to 180 degrees
Center – The fixed point of a circle
Inscribed Angle – An angle whose vertex is on the circle and whose sides are chords of the circle
Intercepted Arc – The arc bound by the chords of an inscribed angle
Secant – A line that intersects a circle in two unique locations
Tangent – A line that intersects a circle once.
Chord – A segment whose endpoints are on a circle
Diameter – A segment whose endpoints are on the circle and passes through the center.
Radius – A segment whose endpoints are the center of the circle and a point on a circle.
Angle Measure – the magnitude of the shortest geometric rotation that will map one ray onto the
other. (the number of degrees it takes to rotate from one ray to the other ray of an angle).
Arc Measure – The measure of an arcs corresponding central angle
Interior of Circle – All points located within the bounded area of the circle
Exterior of Circle- All points located outside the bounded area of the circle