1. Geometry 9.4 Arcs and Chords

2. Theorem In the same circle or in congruent circles: congruent arcs have congruent chords congruent chords have congruent arcs ● O

3. Exercises 110  X Y V U W 22 15 8 10 12 Z 130  Q P R 1. 2. 110 140 110  130 115

4. Theorem A diameter that is perpendicular to a chord bisects the chord and its arc. ● O

5. Exercises Q G H J M K Q A B C Q D E F 12 6 3. 4 3 5 12 200˚ 80 4.5.

6. Theorem In the same circle or in congruent circles: chords equally distant from the center (or centers) are congruent congruent chords are equally distant from the center (or centers) ● O

7. Exercises 9. 10. 11. O A Y B D C X 6 8 8 6 6 DC = ____ 12 H E F K G O M 12√2 6√2 12√2 6√2 N O 9 P Q S R T 18 O 9√3 18√3

8. Exercise (like on your homework) 12. ● 17 30 A B 17 15 The chord is 8 units from circle O. 8 Pythag. Triple 8-15-17 O

9. Exercise (like on your homework) 13. ● 5√3 5 Y X Chord XY is 10√2 units long. Pythag. Thm: 5²+x²= (5√3)² x² + 25 = 75 x² = 50 x = 5√2 2 ● 5√2 = 10√2 5√3 x R

10. Homework pg. 346 CE #1-5 WE # 1-13