Chapter 5: Relationships Within Triangles
5-1: Midsegments of Triangles
Objective:
1. ___________________________________________________________________
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Geometer’s Sketchpad:
1. Construct 3 points.
2. Select the three points and construct segments to form a triangle. Then click “off” of
everything, so nothing is selected.
B
C
Your sketch should look something like this:
3.
4.
5.
6.
7.
8.
A
Select the segment between points A and B.
Construct the midpoint, then unselect everything.
Select the segment between points B and C.
Construct the midpoint, then unselect everything.
Select your two midpoints (D and E).
Construct a segment between them.
Draw a picture of your sketch:
9. Measure segment DE and segment AC, fill them in on your picture above.
10. Make a conjecture:
Theorem 5-1: Triangle Midsegment Theorem
Examples: