1. Time to make a
Wheel of Formulas

2. Central Angle
Vertex ON circle
Vertex INSIDE circle
Vertex OUTSIDE circle
Arc Angle
Formulas

3. Case I: Vertex is AT the centerP C B

4. Case II: Vertex is ON circle
ANGLE
ARC
ARC
ANGLE

5. Case III: Vertex is INSIDE circle
ARC B
ANGLE D
ARC C
Be sure to emphasize that the angles is directly across from the arcs…. Big problem last year
Looks like a PLUS sign!

6. Case IV: Vertex is OUTSIDE circle
ANGLE
small ARC A
LARGE ARC D B

7. Ex. 6 Find m1. 1
15° A D
65° B
m1 = 25

8. Ex. 7 Find mAB. A
27°
70° B
mAB = 16

9. Ex. 8 Find m1.
260° 1
m1 = 80

10. Classwork Practice Worksheets

11. Homework Page 214 #6, 7, 10-12, 14, 16-18