1. Objective
Prove and use properties of triangle midsegments.

2. A midsegment of a triangle is a segment that joins the midpoints of two sides of the triangle. Every triangle has three midsegments.

3. Example :
Find each measure. BD

4. Example:
Find each measure.
mCBD

5. Example:
Find each measure. JL

6. Lesson Quiz: Part I
Use the diagram for Items 1–3. Find each measure.
1. ED
2. AB
3. mBFE

7. Lesson Quiz: Part II
4. Find the value of n.
5. ∆XYZ is the midsegment triangle of ∆WUV. What is the perimeter of ∆XYZ?

8. Graph A, B, and C. Determine the midsegment that joins and in each triangle. Prove that it is the midsegment
Example 1) A (─4, 3) B(0,─1) C (6, 1)
Midpoint of AB : E ________
Midpoint of BC: F ________
Slope of AC : _________
Distance of AC: ________
Slope of EF: _________
Distance of EF : ________