1. Ch4.9_SpecialQuadrilateralsTrapezoids.notebook November 03, 2011
Ch. 4.9
Special Quadrilaterals:
Trapezoids

2. Ch4.9_SpecialQuadrilateralsTrapezoids.notebook November 03, 2011
Trapezoids
2 parallel sides
(bases)
Non­parallel sides are called "legs"
base
base
legleg
Label the bases and legs
Isosceles Trapezoids
Angles on the same LEG
add up to 1800
A + B = 180
A
B
A B
(same­side interior <'s)
Base angles are ≅
Legs are ≅
Find x, y, and z
10 cm
700
x
1100
z
y

3. Ch4.9_SpecialQuadrilateralsTrapezoids.notebook November 03, 2011
m = 1
2
(base 1 + base 2)
Median
Joins midpoints of legs
Base 1
Base 2
Parallel to bases
median = average of bases
4 ft
2 ft
3 ft
1
2
(2 + 4)
1
2
(6)
Solve for x and y for the following trapezoids
and their medians
20
x
25
x + 2
x
yo
9 in
x
x + 5
25 mm
600
600
yo
(y + 50)o
2yo
yo
xo
(x + 30)o
xo
yo
50o