10-8
MAIN IDEA
Quadrilaterals
There are many quadrilaterals
in these fields. How can you
describe some of the different
figures?
I will identify, describe,
and classify
quadrilaterals.
New Vocabulary
rectangle
square
rhombus
parallelogram
trapezoid
All quadrilaterals have 4 sides and 4 angles.
KEY CONCEPT
Quadrilaterals
A rectangle has 4 right angles, with
opposite sides equal and parallel.
A square has 4 right angles, with
opposite sides parallel. All sides
are equal in length.
A rhombus has 4 equal sides and
opposite sides are parallel.
These marks
show equal
sides.
A parallelogram has opposite sides
equal in length and parallel.
A trapezoid has at least 1 pair of
parallel sides.
EXAMPLE
Classify a Quadrilateral
1 Classify the quadrilateral in as many
ways as possible.
It can be classified as a parallelogram,
rectangle, square, and rhombus.
410
Chapter 10 Geometry
0410-0413_CH10L8-105711.indd 410
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Many real-world objects have the shapes of quadrilaterals.
Real-World EXAMPLES
Real-World Shapes
2 VIDEO GAMES Write the type
of quadrilateral that best
describes the game controller.
The game controller has
one pair of parallel sides.
So, it has the shape of
a trapezoid.
3 Identify the shape outlined
in the sculpture.
The opposite sides of
the shape are equal and
parallel. So, the shape is
a parallelogram.
Personal Tutor at ca.gr4math.com
Classify each quadrilateral in as many ways as possible.
See Example 1 (p. 410)
1.
2.
trapezoid 3.
rhombus and parallelogram
square,
rectangle,
rhombus,
and
parallelogram
Write the type of quadrilateral that best describes the shape.
See Examples 2–3 (p. 411)
4.
7.
trapezoid
5.
square
How are a square and a rhombus alike? How are they Sample answer:
different? They both have 4 equal sides. A square has right angles.
Extra Examples at ca.gr4math.com
0410-0413_CH10L8-105711.indd 411
rectangle6.
Lesson 10-8 Quadrilaterals 411
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EXTRA
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See page R27.
Classify each quadrilateral in as many ways as possible.
parallelogram
See Example 1 (p. 410)
rectangle
9.
and
parallelogram
8.
trapezoid
11.
12.
trapezoid
10.
square,
rectangle,
rhombus, and
parallelogram
13.
rectangle and
parallelogram
Write the type of quadrilateral that best describes the shape.
See Examples 2 and 3 (p. 411)
14.
square
15.
17.
trapezoid
18.
rectangle
rectangle
16.
rectangle 19.
trapezoid
20. A quadrilateral has 4 sides with
opposite sides parallel and 4 right
angles. Two sides are longer than the
others. What is the quadrilateral?
rectangle
21. Phillip draws a quadrilateral. It has all
4 sides the same length. Its opposite
sides are parallel. What quadrilateral
did he draw? rhombus
22. OPEN ENDED Draw two quadrilaterals that can be classified
as parallelograms. See Ch. 10 Answer Appendix.
REASONING Tell whether each statement is true or false.
23. A rhombus is a square false
25.
412
24. A rectangle is a parallelogram true
True or false: All squares are rectangles,
but not all rectangles are squares. Explain. See Ch. 10 Answer Appendix.
Chapter 10 Geometry
0410-0413_CH10L8-105711.indd 412
Self-Check Quiz at ca.gr4math.com
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