1. Angles Formed by Secants and Tangents
Section 9.4
Pg. 588
Mrs. Riggle

2. Lesson Objectives Today we will learn how to:
Define angles formed by secants and tangents of circles.
Use theorems about measures of arcs intercepted by these angles.

3. Classifications of Angles with Circles

4. Case 1: Vertex On Circle
Find each measure:
m<BCD
mABC

5. Case 2: Vertex Inside Circle
Find the angle measure:
m<SQR

6. Case 3: Vertex Outside Circle
Find the value of x:

7. Summary

8. You try! Remember -Vertex On Circle = ½ measure of the arc.
-Vertex Inside Circle = ½ sum of the intercepted arcs.
-Vertex Outside Circle = ½ difference of the intercepted arcs.

9. Assignment Independent Work Work to be Submitted
Pgs. 593–594, #11–25, odds.
Check your answers in the back of the textbook when you are finished.
Work to be Submitted
9.4 EdMastery Assignment Due 4p.m. Friday, April 15, 2011.
Have a nice weekend!