Circles Chapter 10 Sections 10.1 –10.7
Parts of a Circle Circle F F F center Use the center to name a circle.
Parts of a Circle chord tangent secant diameter radius Segments & Lines
Radius/diameter radius = ½diameter r = ½ d diameter = 2(radius) Formulas Radius/diameter Circumference radius = ½diameter r = ½ d diameter = 2(radius) d = 2r C = 2∏r or C = ∏d
Types of Angles Central angle Inscribed angle - Vertex is on the center. Inscribed angle - Vertex is on the circle.
Types of Arcs major arc minor arc semicircle M MNO P MO O N MON
Measure of Arcs & Angles minor arc = its central angle major arc = 360 - its central angle 68° 360 – 68 = 292 68° 292°
Measure of Arcs & Angles minor arc = its central angle major arc = 360 - its central angle semicircle = 180 180°
Measure of Arcs & Angles minor arc = its central angle major arc = 360 - its central angle semicircle = 180 inscribed angle = ½minor arc 34° 68°
Arc and Chord Relationships B C D If chords are congruent, then arcs are congruent. then AB CD
If a diameter is perpendicular to a chord, then it bisects the chord. Arc and Chord Relationships If a diameter is perpendicular to a chord, then it bisects the chord. A B G H K
If a diameter is perpendicular to a chord, then it bisects the arc. A Arc and Chord Relationships If a diameter is perpendicular to a chord, then it bisects the arc. A B G H K AH BH
Arc and Chord Relationships Two chords are if and only if they are the same distance from the center. A B C D P O R
Tangent Theorem