Warm­up
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0
62°
1
1. Draw a triangle ABC. Construct median BD.
2
1
3
4
5
2
6
7
3
8
9
10
4
11
12
5
2. Find the slope of the line through (4, 5) and (‐5, 4).
13
14
140°
113
15
Lesson 3.4 Constructing Angle Bisectors
Step 1: Put point on vertex and swing any arc that goes through both sides.
Step 2: Put point on one intersection of arc and side. Swing an arc in the interior of the angle.
0
113°
1
2
3
4
5
2
6
86 58°
7
8
9
10
4
11
12
13
14
5
3
1
0
Step 3: Put point on the other intersection and swing the SAME arc in the interior of the angle.
Step 4: Construct a ray from the vertex through the intersection of the arcs.
15
Lesson 3.4 Constructing Angle Bisectors
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13
5
12
11
10
9
8
3
4
Place a point on the angle bisector. Label it P. Measure the distance from P to each side of the angle.
________ and ________ 7
(Remember what "distance" means!!!!)
6
5
4
84°
3
43
Place another point on the angle bisector. Label it Q.
2
Measure the distance from Q to each side of the angle.
_______ and ________
1
2
What do you notice?
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66°
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0
Homework: Secon 3.4: Page 158 #1‐10