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Geometry A Unit 7 Day 4 Notes
Trapezoids
I. The last type of quadrilateral we will discuss is a TRAPEZOID.
A. Definition: Trapezoid - ___________________________________________
___________________________________________
1. Where trapezoids fit in what we have learned.
Polygons
Triangles
Quadrilaterals
Parallelograms
Rhombus
Hexagons …
Pentagons
Trapezoids
Kites
Rectangles
Squares
2. Parts of a Trapezoid
A
A
B
B
a. Bases - ____________________________________________
2
D
____________________________________________
C
D
1) They can NOT be equal.
A
1
3
D
C
b. Legs - _____________________________________________
B
C
_____________________________________________
1) If they are equal, the trapezoid is an ISOSCELES
trapezoid.
A
B
c. Base Angles - _______________________________________
4
D
__________________________________________________.
C
d. Consecutive Interior Angles - __________________________
__________________________________________________.
II. Examples Using Properties of Trapezoids
A. Since trapezoids fall under the heading of quadrilateral, the property known of all
quadrilaterals applies.
In other words, in a trapezoid, __________________________________.
B. Bases are parallel, so we can use alternate interior and consecutive interior angles
to find measures of angles.
1
 1 = _________
104
2
37
 2 = ________
B. Not all of the angles in the trapezoids below can be found. Find the measures of the
angles that can be found and put a question mark in the spaces provided for those that
can't be found with the given information.
1
2
85

3
4
3
39
91
4
5
 3 = _______  4 = _________
 1 = _______  2 = _______
 5 = ________
 3 = _______
 4 = _______
III. Properties of an Isosceles Trapezoid
A. Use the diagram of an isosceles trapezoid below to make a guess about what
two properties will be true of an isosceles trapezoid.
1. _____________________________________________
(Something about the angles in an isosceles trapezoid.)
2. _____________________________________________
(Something about the diagonals of an isosceles trapezoid.)
IV: Kite - ____________________________________________________________
_________________________________________________________________
_________________________________________________________________
Properties
A. Visually
HW: Trapezoid Practice Worksheet