2. Chapter 10.3

3. Essential Question  What are the properties of chords?

4. What’s a chord again?  A chord is a segment inside a circle with endpoints on the circle.  Any chord will divide a circle into 2 arcs, a major and minor arc.

5. If there are any 2 chords of the same length, then their arcs are congruent.

6. What are the measures of arcs AB, AE, and BD? 360 – 75 – 75 = 210 210 ÷2 = 105 105º

7. Find the measures of arcs AB and DB… Hint: they should be the same! 360 – 128= 232 232 ÷2 = 116

9. What do you know about the 2 segments? 3x + 7 = 4x 7 = x

10. Find x 5x - 6 = 2x + 9 3x - 6 = 9 3x = 15 x = 5

11. Find x 6x + 9 = 8x - 13 9 = 2x - 13 22 = 2x11 = x

12. The chords are congruent when they are the same distant from the center.

13. What do we know about the 2 segments? 5x - 7 = 18 5x = 25 x = 5

14. If the 2 chords are congruent, what do we know about AQ and BQ? 4x + 1 = x + 8 3x + 1 = 8 3x = 7 x = 2.333

15. Find the given arc If the diameter is perpendicular to a chord then it splits the chord in half. Find the other 2 arcs A circle is 360º, so … 360 – 55 – 55 = 250 250 ÷ 2 = 125° 125 °

16. Find the missing arcs If there are 4 arcs of equal size, what do you divide 360 by? 4 360 ÷ 4 = 90

17. Classzone eWorkbook 10.3