2 Circle Definition Circle : The set of coplanar points equidistant from a given point.The given point is called the CENTER of the circle.The distance from the center to the circle is called the RADIUS.CenterRadius
3 Definitions Chord : The segment whose endpoints lie on the circle. Diameter :A chord that contains the center of the circle.Tangent :A line in the plane of the circle that intersects the circle in exactly one point.TangentPoint of Tangency :ChordThe point where the tangent line intersects the circle.DiameterSecant :A line that contains a chord.Secant
4 Example: In the following figure identify the chords, radii, and diameters. BFCERadii:Diameter:
5 Definitions Congruent Circles : Concentric circles : Circles that have congruent radii.22Concentric circles :Circles that lie in the same plane and have the same center.
6 Polygons Inscribed Polygon: A polygon inside the circle whose vertices lie on the circle.Circumscribed Polygon :A polygon whose sides are tangent to a circle.
7 ARCSArcs :The part or portion on the circle from some point B to C is called an arc.ABCExample:BSemicircle:An arc that is equal to 180°.OAExample:C
8 Minor Arc & Major Arc Minor Arc : A minor arc is an arc that is less than 180°A minor arc is named using its endpoints with an “arc” above.AExample:Major Arc:A major arc is an arc that is greater than 180°.BBOA major arc is named using its endpoints along with another point on the arc (in order).AExample:C
9 Example: ARCS Minor Arc: Major Arc: Semicircle: Identify a minor arc, a major arc, and a semicircle, given that is a diameter.Minor Arc:ACDEFMajor Arc:Semicircle: