1. Triangles and Trapezoids
Midsegments
Triangles and Trapezoids

2. Midsegment
What is it? Connects 2 midpoints of the sides (legs) How many does a triangle have? 3 How many does a trapezoid have? 1

3. Midsegment in a Triangle
What is special about midsegments in Triangles? If all 3 are drawn you construct 3 congruent triangles Midsegments are parallel to the third side ( side not touch) and is half the length of the third side

4. Prove midsegment Properties
Parallel and Half Prove Triangles are similar Proportional sides and congruent Angles. S R
BD is midsegment of ACE G
C = C
Reflexive
BC = 1/2 AC
Def Midseg
DC=1/2 AC
ACE ~BCD
SAS
BD = 1/2 AF
Def Similar
<BDC=<AEC
BD || AE
Converse of Corr

5. Example

6. Trapezoid Midsegment
Trapezoid is part of a triangle Midsegment is parallel to both bases What about the length? Average of the two bases

7. Example

8. Homework
Review pg and 8 Pg Honors 10