1. Warm up 2 – 18 evens only. This will be graded in 10 minutes. 2.79
27.93
61.78
138.4
7.16
309.4°
107 ° ° °

2. 9.2 Tangents and Secants Tangents and secants are LINES.
A tangent line intersects the circle at exactly ONE point.
A secant line intersects the circle at exactly TWO points.

3. A little extra information
The word tangent comes from the Latin word meaning to touch
The word secant comes from the Latin word meaning to cut.

4. Important Theorems Tangent Theorem:
If a line is tangent to a circle, then the line is perpendicular to a radius of the circle drawn to the point of tangency.
The line AB is tangent to circle C at B.
How could we prove that segment CB and line AB are perpendicular?

5. Converse of the Tangent Theorem
Go waaaayyy back… how do we get a converse statement?
What would be the Converse of the Tangent Theorem?
If a line is perpendicular to a radius of a circle at its endpoint on the circle, then the line is tangent to the circle.

6. Radius and Chord Theorem
A radius that is perpendicular to the chord of a circle bisects the chord.
QR = 3
What is the measure of RS?
XR = 7 and WR = 2
Find the missing measures of the remaining segments.
RZ =
RY =
XW =
WZ =
XZ = 7
6.7
13.4

7. I need 2 volunteers to hand out whiteboards and markers.
Let’s Practice
I need 2 volunteers to hand out whiteboards and markers.

9. Your assignment
Pg 577; 10-13, 19-26
Pg 846, Lesson 9.2, 1-6