1. Objective
Use properties of triangle midsegments.

2. __________________ – a perpendicular segment from a vertex to the line containing the opposite side.
Every triangle has three altitudes. An altitude can be inside, outside, or on the triangle.

3. ________________– a segment whose endpoints are a vertex of the triangle and the midpoint of the opposite side.
Every triangle has three medians.

4. ______________– a segment that joins the midpoints of two sides of the triangle. Every triangle has three midsegments, which form the midsegment triangle.

6. Example 1A: Using the Triangle Midsegment Theorem
Find each measure. BD

7. Example 1B: Using the Triangle Midsegment Theorem
Find each measure.
mCBD

8. Check It Out! Example 2a
Find each measure. JL

9. Check It Out! Example 2b
Find each measure. PM

10. Check It Out! Example 2c
Find each measure.
mMLK

11. Example 3: Indirect Measurement Application
In an A-frame support, the distance PQ is 46 inches. What is the length of the support ST if S and T are at the midpoints of the sides?