1. Lesson 5.3
Goal: The learner will use angle bisectors to find distance relationships.

2. Angle Bisector: A line, segment or ray that divides an angle in half

3. Properties of Angle Bisectors
If a point is on the angle bisector, then it’s equidistant to the sides of the angle.

4. Find the measure of G 7 J 7 F H

5. Algebra Of Course For what value of x does P lie on the bisector of B

6. Find the value of x.
(3x + 5)°
(4x-6)°
p. 313 # 3-17
End of Day 1

7. Point of Concurrency
Incenter: point where all three angle bisectors intersect.
Open TI CAS.

8. Inscribed Circle
The incenter is equidistant to all 3 sides of a triangle.
Inscribed circle: incenter is the center and touches all 3 sides of the triangle.

9. Folding Angle Bisectors
Fold an angle bisector by lining up two sides on top of each other and fold through the angle.
Do this for all 3 angles.

10. Construct the Inscribed Circle
Set your compass with one end on the incenter and the other on the triangle’s side.
Swing a 360° arc.
TI CAS..\..\..\..\..\Documents\TI-Nspire\documents\Points of concurrency.tns

11. In the diagram, N is the incenter of ABC. Find ND.
p. 314 #19, 20, 22, 24, 28