1. Geometry 5-4 Midsegments
Midsegment of a triangle: a segment that connects the midpoints of two sides of the triangle.
Midsegment Triangle: the triangle formed by the 3 midsegments
Midpoints: X, Y, Z
Midsegments: XY, YZ, ZX
Midsegment triangle: ΔXYZ

2. Midsegment Theorem
The midsegment is ½ the length of its parallel side.
If BC = 30
DE = 15 A B C E D F
BF = FC = 15
If EF = 12
AB = 24
AD = DB = 15

3. Midsegment Angles
All of the angles of the midsegment triangle are the same as the original triangle. A
60° D E
70°
50° C B F

4. Example
Find the perimeter and area of both the original and midsegment triangle. 24 26 10

5. Example Solve for the value of x given DE and EF are midsegments. AC B F