1. Secants, Tangents, & Angle Measures
Section 10-6

2. A secant of a circle contains a chord of the circle.
secant – a line that intersects a circle in exactly 2 points.
A secant of a circle contains a chord of the circle.

3. Theorem
If a secant and a tangent intersect at the point of tangency, then the measure of each angle formed is one-half the measure of its intercepted arc.

4. 60o
120o

5. Theorem 10.12
If 2 secants intersect in the interior of a circle, then the measure of an angle formed is ½ the sum of the measures of the arcs intercepted by the angle and its vertical angle.

6. 60o
50o
40o

7. Theorem 10.14
If 2 secants, a secant and a tangent, or 2 tangents intersect in the exterior of a circle, then the measure of the angle formed is ½ the positive difference of the measures of the intercepted arc.

8. 55o
30o
140o

9. Joke Time
What is an insect that’s not feeling well?
Secant (sick ant)

10. Who was a famous person that was not very healthy?
“I sick” Newton