1. 1. Draw 4 concentric circles 2. Draw a circle with r = 4 and center A. 3. What is the diameter of the circle? 4. Explain the difference between a secant & a chord 5. What do you know about a tangent line and the radius drawn to the point of tangency? Session 29

2. Math II UNIT QUESTION: What special properties are found with the parts of a circle? Standard: MM2G1, MM2G2 Today’s Question: How do we use angle measures to find measures of arcs? Standard: MM2G3.a,d

4. P A B C Central Angle : An Angle whose vertex is at the center of the circle Minor ArcMajor Arc Less than 180° More than 180° AB ACB To name: use 2 letters To name: use 3 letters  APB is a Central Angle

5. P E F D Semicircle: An Arc that equals 180° EDF To name: use 3 letters

6. THINGS TO KNOW AND REMEMBER ALWAYS A circle has 360 degrees A semicircle has 180 degrees Vertical Angles are Equal

7. measure of an arc = measure of central angle A B C Q 96  m AB m ACB m AE E = = = 96° 264° 84°

8. Arc Addition Postulate A B C m ABC = m AB + m BC

9. Tell me the measure of the following arcs. 80  100  40  140  A B C D R m DAB = m BCA = 240  260 

10. Congruent Arcs have the same measure and MUST come from the same circle or of congruent circles. 45 A B C D 110

11. Classwork Workbook Page 204 #12-24

12. Homework: TEXT Book: page 193 #9-23 page 201 #1-10