Circles

1. Circles Chapter 10 Sections 10.1 –10.7

2. F Parts of a Circle Circle F F center Use the center to name a circle.

3. Parts of a Circle chord tangent secant diameter radius Segments & Lines

4. Formulas • Radius/diameter • Circumference radius = ½diameter r = ½ d diameter = 2(radius) d = 2r C = 2∏r or C = ∏d

5. Types of Angles Central angle - Vertex is on the center. Inscribed angle - Vertex is on the circle.

6. MNO MO MON Types of Arcs major arc minor arc semicircle M P O N

7. Measure of Arcs & Angles minor arc = its central angle major arc = 360 - its central angle 68° 360 – 68 = 292 68° 292°

8. Measure of Arcs & Angles minor arc = its central angle major arc = 360 - its central angle semicircle = 180 180°

9. Measure of Arcs & Angles minor arc = its central angle major arc = 360 - its central angle semicircle = 180 inscribed angle = ½minor arc 34° 68°

10. A C B D then AB CD Arc and Chord Relationships If chords are congruent, then arcs are congruent.

11. A G H B Arc and Chord Relationships If a diameter is perpendicular to a chord, then it bisects the chord. K

12. A G H B AH  BH Arc and Chord Relationships If a diameter is perpendicular to a chord, then it bisects the arc. K

13. A O C P R B D Arc and Chord Relationships Two chords are  if and only if they are the same distance from the center.