1. 10.3 Arcs and Chords What you’ll learn: 1.To recognize and use relationships between arcs and chords. 2.To recognize and use relationships between chords and diameters.

2. Theorem 10.2 In a circle or in congruent circles, two minor arcs are congruent iff their corresponding chords are congruent. If then AB=CD or if AB=CD, then A B C D

3. Inscribed and Circumscribed Inscribed polygon – a polygon in which all vertices lie on the circle. BCDE is inscribed in circle A Circle A is circumscribed about the polygon – the circle contains all the vertices of the polygon. A BC DE

4. Theorem 10.3 In a circle, if a diameter (or radius) is perpendicular to a chord, then it bisects the chord and its arc. If FD is a radius, and FD is perpendicular to CB, then CE=EB and CD=DB. A B C D E F

5. Theorem 10.4 In a circle, or in congruent circles, 2 chords are congruent iff they are equidistant from the center. If FG=GE, then AB=CD. or If AB=CD, then FG=GE. A B C D E F G

6. Circle W has a radius of 10 cm. Radius WL is perpendicular to chord HK, which is 16 cm long. a.If =53, find b.Find JL M HK J L

7. Chords EF and GH are equidistant from the center. If the radius of circle P is 15 and EF=24, find PR and RH E F P G R H Q

8. The diameter of a circle is 60 inches, and a chord of the circle is 48 inches long. How far is the chord from the center of the circle.

9. Homework p. 540 12-34 even, 54-59 all