1. Warm up

2. 3.7 Midsegments of Triangles & Trapezoids
FYI
3.7 today
3.8 next time
Review the time after that...
Then… Chapter 3 test the time after that

3. Midsegment of a triangle
A segment whose endpoints are the midpoints of two sides. It is parallel to one side of the triangle and its measure is ½ of that side.
If AE = 15
Find the measure of BD A B C D E X
½ X
midsegment
BD = 7.5

4. TRY THIS AND THIS 3X - 5 X + 2 A B C D E 3X – 5 = 2(X + 2)
AE = 22 units
BD = 11
X2 + 1 = 2 (X)
X2 – 2X + 1 = 0
(X – 1) (X – 1) = 0
X = 1
BD = 1 units
AE = 2 units
AND THIS A B C D E
X2 + 1 X

5. Midsegment of a Trapezoid
A segment whose endpoints are the midpoints of the NON-PARALLEL sides.
It’s parallel to the bases and
its measure = (Sum of the bases) 2
BASES
Midsegment

6. Try this
Find the lengths of the parallel segments when x = 2 A B C Z Y M X
X + 5 ?
AM = 2
BY = 7
CZ = 12
Check to make sure these numbers work…
Find ?
= 7 2
? = X + 10
YEA!!

7. Try this… and this… BY = 28 C X Y B A Z If AZ = 25 and
CX = 31, find BY
BY = 28
and this… C X
If AZ = x2 + 4x - 36 and
CX = x2 + 2x - 40 and BY = 16
Find the lengths of the bases Y B A Z

8. Find the lengths of BD and AE if
Uno mas
Find the lengths of BD and AE if
BD = 4x – 4 and AE = 10x – 12
2(4x-4) = 10x – 12
8x – 8 = 10x -12
4 = 2x
X = 2
BD = AE = 8 B C D E A

9. Assignment
Pg 186, 5-8, 10-16, 22, 28-30, 32-40