1. Circles
Chapter 10
Sections 10.1 –10.7

2. This chapter will be separated into TWO tests.
1st test – Sections
2nd test – Sections

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

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

5. 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

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

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

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

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

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

11. Arc and Chord RelationshipsB C D
If chords are congruent, then arcs are congruent.
then AB CD

12. 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

13. 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

14. 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

15. Test 10.1-10.4 total problem - 57 matching (12)
arc or angle with various diagrams (9)
arcs and angles with one diagram (18)
radius or diameter with one diagram (8)
chord/segment diagrams (10)