Quick Check
Name
1. W
hichquadrilateralisNOTa
parallelogram?
8-6B
2. H
owarearhombusandasquare
alike?
A square
A Bothhaveequalangles.
B trapezoid
B Bothhaveequalsides.
C rhombus
C Bothhaveexactlyonepairof
parallelsides.
D rectangle
D Neitherhaveanysetsof
parallelsides.
3. Howareaparallelogramandatrapezoiddifferent?
A Aparallelogramhasonly1pairofparallelsides,butatrapezoidhas2.
B Atrapezoidhasonly1pairofparallelsides,butaparallelogramhas2.
C Atrapezoidhas4rightangles,butaparallelogramdoesn’tneedtohave
4 rightangles.
D Aparallelogramhas4rightangles,butatrapezoiddoesn’tneedtohave
4 rightangles.
4. W
ritingtoExplain Drawaquadrilateralthatisbotharectangle
andarhombus.Whattypeofspecialquadrilateraldidyou
draw?
Q 8•6B
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Par tner
Talk
Sh
k.
are
wor
your t
hinking while you
Put 1 2 3 4 in a bag.
Get Started
or
Choose A, B, C, D, E, or F .
Pick a tile. Pick two tiles if your group has only two students.
Tell your group if the word next to your number names the shape.
Discuss: Which three names describe the geometric figure? Why?
Decide: Which name does not describe the figure? Why not?
For Each
Round
B
A
C
1
rectangle
1
equilateral
1
quadrilateral
2
rhombus
2
isosceles
2
parallelogram
3
parallelogram
3
quadrilateral
3
rectangle
4
trapezoid
4
acute
4
rhombus
D
E
F
1
quadrilateral
1
parallelogram
1
4-sided figure
2
parallelogram
2
quadrilateral
2
quadrilateral
3
trapezoid
3
rectangle
3
kite
4
4-sided figure
4
rhombus
4
trapezoid
If you have
more time
Make up a “Think Together” question about quadrilaterals.
Challenge your classmates to think together to answer your question.
Center Activity H 8-6B
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Par tner
Talk
Sh
Get Started
or
For Each
Round
A
Put 1 2 3 4 in a bag.
Choose A, B, C, D, E, or F .
Pick a tile. Pick two tiles if your group has only two students.
Answer the question for the shape next to your number.
Discuss: Which three shapes have the given name? Why? Decide: Which shape does not have the given name? Why not? Is the shape
a quadrilateral?
Why or why not?
B
Is the shape
a trapezoid?
Why or why not?
C
1
1
1
2
2
2
3
3
3
4
4
4
D
Is the shape
a rectangle?
Why or why not?
E
Is the shape
a rhombus?
Why or why not?
F
1
1
1
2
2
2
3
3
3
4
4
4
If you have
more time
k.
are
wor
your t
hinking while you
Is the shape
a parallelogram?
Why or why not?
Is the shape
a square?
Why or why not?
Make up a “Think Together” question about quadrilaterals.
Challenge your classmates to think together to answer your question.
Center Activity HH 8-6B
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Reteaching
Name
8-6B
Classifying Quadrilaterals
How are special quadrilaterals related to each other?
This “family tree” shows how special quadrilaterals are related to
each other.
Quadrilaterals
Trapezoid
Parallelogram
Rectangle
Rhombus
Square
Tell whether each statement is true or false.
1. All squares are rhombuses.
2. Every trapezoid is a rectangle.
3. Squares are special parallelograms.
4. All quadrilaterals are squares.
5. All rhombuses are rectangles.
6. Every trapezoid is a quadrilateral.
7. Rhombuses are special parallelograms.
8. All rectangles are quadrilaterals.
R 8•6B
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Practice
Name
8-6B
Classifying Quadrilaterals
In 1–8, tell whether each statement is true or false. Remember, for
a statement to be true is has to be true in EVERY circumstance.
1. A rectangle is a quadrilateral.
2. All parallelograms are trapezoids.
3. A quadrilateral is a square.
4. A quadrilateral is a trapezoid.
5. A rhombus is a rectangle.
6. A trapezoid is a parallelogram.
7. A square is a rectangle.
8. A rectangle is a quadrilateral.
9. Which shows the most likely side lengths for a parallelogram?
A 9, 4, 9, 4
B 9, 9, 9, 4
C 4, 4, 4, 9
D 4, 9, 9, 6
10. Draw 3 different quadrilaterals with 2 pairs of parallel sides. What
are the names of the special quadrilaterals you have drawn?
11. A parallelogram has one side that is 9 millimeters and one side
that is 13 millimeters. What is the perimeter of the parallelogram?
12. Writing to Explain What characteristics help you tell the
difference between a parallelogram and a trapezoid? Explain.
P 8•6B
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Enrichment
Name
8-6B
Perfect Polygons!
Polygonshavemanydifferentproperties.Onepropertyofpolygons
isthenumberofdiagonalsthatcanbedrawnintheirinteriors.
Adiagonalofapolygonisalinesegmentdrawnfromonevertex
toanother.Adiagonalhasbeendrawnintherectanglebelow.
1. Drawallofthediagonalsinthepolygonsbelow.Countthenumberof
diagonalsineach.Then,fillinthetablewiththatinformation.
Triangle
Quadrilateral Pentagon Hexagon Heptagon Octagon
Number of
Sides
3
4
Number of
Diagonals
0
2
5
Whatpatterndidyoufind?
Theformulaforfindingthenumberofdiagonalsinapolygonisx(x–3)÷ 2,
wherexisthenumberofsides.Findthenumberofdiagonalsineachpolygon.
2. Decagon(10sides)
3. Dodecagon(12sides)
4. Pentadecagon(15sides)
5. Icosagon(20sides)
6. Hectagon(100sides)
E 8•6B
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Teaching Tool
Name
46
Classifying Quadrilaterals
List the letter of each figure in each group.
Trapezoids
Parallelograms
Rectangles
Squares
Rhombuses
G
L
V
Q
M
R
O
U
N
S
TT 46
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