Learning Objective
Name __________________________
Today, we will find the perimeter of a polygon.
CFU
What are we going to do today?
Activate (or Provide) Prior Knowledge
How many sides does each shape have?
What are the lengths of the sides of each shape?
1.
3 in
6 in
2.
3 sides
3 in
4 sides
3 in
4 in
5 in
6 in
CFU
Students, you already know that a shape’s sides have a length.
Today, we will use the side lengths of a polygon to find the perimeter.
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3rd Grade Measurement and Geometry 1.3 (3Q)
Find the perimeter of a polygon with integer sides.
Lesson to be used by EDI-trained teachers only.
Concept Development
A polygon is a closed plane1 figure2 with straight sides.
1 flat
2 shape
Polygons
Units
NOT Polygons
centimeters (cm)
inches (in)
feet (ft)
meters (m)
Perimeter is the length of the distance around a polygon.
• Side lengths can be measured in different units3.
3
amounts of measurement
Perimeter
3 in + 4 in + 5 in = 12 in
5 in
3 in
The perimeter of the
polygon is 12 in.
4 in
3 in
4 in
5 in
12 in
CFU
On your whiteboard, draw an example of a polygon. Why is your example a polygon?
Which of the following lengths could be the perimeter of the polygon below? How do you know?
A
In your own words, what is perimeter? Perimeter is ______________.
B
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3rd Grade Measurement and Geometry 1.3 (3Q)
Find the perimeter of a polygon with integer sides.
Lesson to be used by EDI-trained teachers only.
Skill Development/Guided Practice
A polygon is a closed plane figure with straight sides.
Perimeter is the length of the distance around a polygon.
Units
centimeters (cm)
inches (in)
Find the perimeter of a polygon.
Step #1: Add all side lengths of the polygon.
a. Mark off side lengths as they are used.
Step #2: Interpret4 the perimeter using the correct units. “The perimeter is ___ because __________.”
4
feet (ft)
meters (m)
explain
1.
3 + 5 + 4 = 12 in
5 in
3 in
5 ft
5 ft
5 + 5 + 5 + 5 = 20 ft
5 ft
2m
2m
2m
4 ft
4.
5 + 2 + 2 + 2 + 3 + 4 = 18 m
5m
3m
4m
The perimeter is 18 m
because it is the distance
around the polygon.
CFU
(#1) How did I/you add the side lengths of the polygon?
(#2) How did I/you interpret the perimeter?
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4 ft
= 10 ft
2ft
The perimeter is 10 ft
because it is the distance
around the polygon.
8m
2 + 8 + 2 + 8 = 20 m
2m
The perimeter is 20 ft
because it is the distance
around the polygon.
5 ft
5.
4+ 4+ 2
The perimeter is 12 in
because it is the distance
around the polygon.
4 in
3.
2.
2m
8m
The perimeter is 20 m
because it is the distance
around the polygon.
2 cm
6.
2 cm
3 cm
3 cm
3 + 3 + 2 + 2 + 5 + 5 = 20 cm
5 cm
The perimeter is 20 cm
because it is the distance
around the polygon.
5 cm
3rd Grade Measurement and Geometry 1.3 (3Q)
Find the perimeter of a polygon with integer sides.
Lesson to be used by EDI-trained teachers only.
Relevance
A polygon is a closed plane figure with straight sides.
Perimeter is the length of the distance around a polygon.
1. Finding the perimeter of polygons will help you use measuring in real life.
Sarah’s teacher tells her she will have to run a lap
around the soccer field for P.E. class. Sarah wonders
how many feet she will run around the soccer field.
2. Finding the perimeter of polygons will help you build things.
For Father’s Day, Jack is going to build his father a
new fence for the swimming pool. Before he can start
building, he needs to know the perimeter of the pool.
3. Finding the perimeter of polygons will help you do well on tests.
CFU
Does anyone else have another reason why it is relevant to find the perimeter of a polygon? (pair-share) Why is it relevant to find the
perimeter of a polygon? You may give me one of my reasons or one of your own. Which reason is most relevant to you? Why?
DataWORKS Educational Research
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©2012 All rights reserved.
Comments? feedback@dataworks-ed.com
3rd Grade Measurement and Geometry 1.3 (3Q)
Find the perimeter of a polygon with integer sides.
Lesson to be used by EDI-trained teachers only.
A polygon is a closed plane figure with straight sides.
Perimeter is the length of the distance around a polygon.
Units
Skill Closure
Find the perimeter of a polygon.
centimeters (cm)
inches (in)
Step #1: Add all side lengths of the polygon.
a. Mark off side lengths as they are used.
Step #2: Interpret the perimeter using the correct units. “The perimeter is ___ because __________.”
1.
4 cm
2.
2 cm
2 cm
2 + 2 + 1 = 5 cm
The perimeter is 5 cm
because it is the distance
around the polygon.
1 cm
2 cm
feet (ft)
meters (m)
2 + 4 + 2 + 4 = 12 cm
2 cm
4 cm
The perimeter is 12 cm
because it is the distance
around the polygon.
Constructed Response Closure
Which of the following lengths could represent the
perimeter of the polygon to the left? Explain your answer.
A
B
______________________________________________
______________________________________________
Summary Closure
What did you learn today about finding the perimeter of a polygon? (pair-share)
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3rd Grade Measurement and Geometry 1.3 (3Q)
Find the perimeter of a polygon with integer sides.
Lesson to be used by EDI-trained teachers only.
Independent Practice
Name ________________________
A polygon is a closed plane figure with straight sides.
Perimeter is the length of the distance around a polygon.
Units
Find the perimeter of a polygon.
centimeters (cm)
inches (in)
Step #1: Add all side lengths of the polygon.
a. Mark off side lengths as they are used.
Step #2: Interpret the perimeter using the correct units. “The perimeter is ___ because __________.”
1.
2.
4 cm
4 cm
4 cm
4 cm
4 + 4 + 4 + 4 = 16 cm
The perimeter is 16 cm
because it is the distance
around the polygon.
3.
3 ft
3 ft
3 + 3 + 3 + 3 + 3 = 15 in
3 in
3 in
3 in
3 in
3 in
The perimeter is 15 in
because it is the distance
around the polygon.
3 + 7 + 3 + 7 = 20 ft
3 ft
3 ft
The perimeter is 20 ft
because it is the distance
around the polygon.
7 ft
4.
4 cm
5 + 4 + 3 = 12 cm
3 cm
5 cm
The perimeter is 8 ft
because it is the distance
around the polygon.
2 ft
5.
3 + 3 + 2 = 8 ft
7 ft
6.
feet (ft)
meters (m)
The perimeter is 12 cm
because it is the distance
around the polygon.
2 ft
4 + 2 + 2 + 2 + 2 + 4 = 16 ft
2 ft
4 ft
2 ft
2 ft
4 ft
The perimeter is 16 ft
because it is the distance
around the polygon.
DataWORKS Educational Research
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©2012 All rights reserved.
Comments? feedback@dataworks-ed.com
3rd Grade Measurement and Geometry 1.3 (3Q)
Find the perimeter of a polygon with integer sides.
Lesson to be used by EDI-trained teachers only.
Periodic Review 1
Name ________________________
A polygon is a closed plane figure with straight sides.
Perimeter is the length of the distance around a polygon.
Units
Find the perimeter of a polygon.
centimeters (cm)
inches (in)
Step #1: Add all side lengths of the polygon.
a. Mark off side lengths as they are used.
Step #2: Interpret the perimeter using the correct units. “The perimeter is ___ because __________.”
1.
2.
6 cm
6 cm
6+6+6+6
6 cm
6+5+6+5
6 ft
2 ft
= 22 ft
2 ft
2 + 2 + 2 + 2 = 8 ft
2 ft
The perimeter is 8 ft
because it is the distance
around the polygon.
3 + 4 + 3 = 10 in
The perimeter is 10 in
because it is the distance
around the polygon.
3 in
4.
7m
7m
The perimeter is 22 ft
because it is the distance
around the polygon.
5 ft
2 ft
4 in
The perimeter is 24 cm
because it is the distance
around the polygon.
5 ft
6 ft
5.
= 24 cm
3 in
6 cm
3.
feet (ft)
meters (m)
7m
7m
7m
6.
8m
4m
The perimeter is 35 m
because it is the distance
around the polygon.
8 +8 + 8 + 4
8m
8m
7 + 7 + 7 + 7 + 7 = 35 m
= 28 m
The perimeter is 28 m
because it is the distance
around the polygon.
DataWORKS Educational Research
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©2012 All rights reserved.
Comments? feedback@dataworks-ed.com
3rd Grade Measurement and Geometry 1.3 (3Q)
Find the perimeter of a polygon with integer sides.
Lesson to be used by EDI-trained teachers only.
Periodic Review 2
Name ________________________
A polygon is a closed plane figure with straight sides.
Perimeter is the length of the distance around a polygon.
Units
Find the perimeter of a polygon.
centimeters (cm)
inches (in)
Step #1: Add all side lengths of the polygon.
a. Mark off side lengths as they are used.
Step #2: Interpret the perimeter using the correct units. “The perimeter is ___ because __________.”
1.
2 cm
2+ 2+ 2+ 2
7 ft
7 ft
7 ft
7 ft
8 ft
7 + 7 + 7 + 7 = 28 ft
The perimeter is 28 ft
because it is the distance
around the polygon.
4 + 8 + 6 + 7 = 25 ft
6 ft
4 ft
7 ft
The perimeter is 25 ft
because it is the distance
around the polygon.
3m
6m
3m
The perimeter is 8 cm
because it is the distance
around the polygon.
2 cm
5.
2.
2 cm
2 cm
3.
= 8 cm
6m
4.
5 cm
3m
3m
5 cm
5 cm
5 cm
5 cm
6.
2m
2m
2m
feet (ft)
meters (m)
3 + 3 + 6 + 3 + 3 + 6 = 24 m
The perimeter is 24 m
because it is the distance
around the polygon.
5 + 5 + 5 + 5 + 5 = 25 cm
The perimeter is 25 cm
because it is the distance
around the polygon.
2+ 2+ 2 =6m
The perimeter is 6 m
because it is the distance
around the polygon.
DataWORKS Educational Research
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©2012 All rights reserved.
Comments? feedback@dataworks-ed.com
3rd Grade Measurement and Geometry 1.3 (3Q)
Find the perimeter of a polygon with integer sides.
Lesson to be used by EDI-trained teachers only.
Periodic Review 3
Name ________________________
A polygon is a closed plane figure with straight sides.
Perimeter is the length of the distance around a polygon.
Units
Find the perimeter of a polygon.
centimeters (cm)
inches (in)
Step #1: Add all side lengths of the polygon.
a. Mark off side lengths as they are used.
Step #2: Interpret the perimeter using the correct units. “The perimeter is ___ because __________.”
1.
5 cm
6 + 5 + 4 = 15 cm
6 cm
10 ft
5 ft
3 cm
4 + 3 + 3 + 4 + 3 = 17 cm
5 ft
10 ft
The perimeter is 40 ft
because it is the distance
around the polygon.
6 ft
4 + 6 + 4 + 6 = 20 ft
4 ft
3 cm
3 + 3 + 3 + 3 = 12 in
The perimeter is 12 in
because it is the distance
around the polygon.
3 in
10 + 5 + 5 + 5 + 5 + 10 = 40 ft 4.
5 ft
5.
3 in
3 in
The perimeter is 15 cm
because it is the distance
around the polygon.
5 ft
3.
3 in
2.
4cm
feet (ft)
meters (m)
4 ft
6 ft
4 cm
6.
4 cm
3 cm
The perimeter is 17 cm
because it is the distance
around the polygon.
6m
8 + 6 + 8 + 6 = 28 m
8m
The perimeter is 20 ft
because it is the distance
around the polygon.
8m
6m
The perimeter is 28 m
because it is the distance
around the polygon.
DataWORKS Educational Research
(800) 495-1550 •www.dataworks-ed.com
©2012 All rights reserved.
Comments? feedback@dataworks-ed.com
3rd Grade Measurement and Geometry 1.3 (3Q)
Find the perimeter of a polygon with integer sides.
Lesson to be used by EDI-trained teachers only.
EDI – Cognitive, Teaching and English Learners Strategies
Learning Objective : Find the perimeter of a polygon.
Cognitive Strategies
Teaching Strategies
Elaboration
Demonstration
Targeted vocabulary: polygon, plane, figure, perimeter, interpret, units
Language Strategies
Vocabulary Words
Academic
interpret
Content
polygon, perimeter
Support
plane figure, units
Multiple-Meaning
plane
Synonym
Vocabulary
Strategy
Definition
polygon, figure, perimeter, interpret, units
Homophone
Internal Context Clue
Listen, Speak
Read
Similar Sounds
Tracked Reading
Decoding Rules
Write
Writing
Content Access Strategies
Comprehensible
Input
Cognates
Graphic Organizer
Contextual Clues
Contextualized
Definitions
Pictures
DataWORKS Educational Research
(800) 495-1550 •www.dataworks-ed.com
©2012 All rights reserved.
Comments? feedback@dataworks-ed.com
3rd Grade Measurement and Geometry 1.3 (3Q)
Find the perimeter of a polygon with integer sides.
Lesson to be used by EDI-trained teachers only.