Introduction to Perimeter


Our Introduction to Perimeter lesson plan teaches students what perimeter is and how to measure it. Students complete practice problems where they find the perimeter of polygons and other objects. They will also learn some real world applications using perimeter.

Included with this lesson are some adjustments or additions that you can make if you’d like, found in the “Options for Lesson” section of the Classroom Procedure page. One of the optional additions to this lesson is to expand the activity by bringing your students outside and having them measure objects that they find outdoors.

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What our Introduction to Perimeter lesson plan includes

Lesson Objectives and Overview: Introduction to Perimeter teaches students the definition of perimeter and how to find the perimeter of various polygons and other objects. This engaging lesson incorporates collaborative learning and reinforces the concepts with students as they identify real-world uses for perimeter. This lesson is for students in 1st grade, 2nd grade, 3rd grade, and 4th grade.

Classroom Procedure

Every lesson plan provides you with a classroom procedure page that outlines a step-by-step guide to follow. You do not have to follow the guide exactly. The guide helps you organize the lesson and details when to hand out worksheets. It also lists information in the blue box that you might find useful. You will find the lesson objectives, state standards, and number of class sessions the lesson should take to complete in this area. In addition, it describes the supplies you will need as well as what and how you need to prepare beforehand. For this lesson, the supplies you will need are string, scissors, scratch paper, rulers, and the handouts. To prepare for this lesson ahead of time, you can measure and cut the string as needed, gather the supplies, and copy the handouts.

Options for Lesson

Included with this lesson is an “Options for Lesson” section that lists a number of suggestions for activities to add to the lesson or substitutions for the ones already in the lesson. The suggestions for this lesson are adjustments for the activity worksheet. For the activity, you could provide students with longer pieces of string to measure with. You could also bring them outside and have them measure objects that they find outdoors. Students could also measure the perimeter of other rooms in the school, like the gym or library. You could also have them convert inches into feet when measuring larger objects. They can also measure the whole perimeter of the school or the school parking lot using a pre-drawn sketch to note the lengths and widths on. Finally, students could use a tape measure of yardstick instead of string to measure with.

Teacher Notes

The teacher notes page includes a paragraph with additional guidelines and things to think about as you begin to plan your lesson. It notes that it’s very important for students to learn how to find the perimeter of shapes and to understand how perimeter is used in the real world. It also states that you could pair this lesson with a lesson that introduces area. This page also includes lines that you can use to add your own notes as you’re preparing for this lesson.


What is Perimeter?

The Introduction to Perimeter lesson plan includes three content pages. The lesson begins by defining perimeter as the distance around the outside of a shape or an area. We usually measure this distance in inches, feet, or miles. For example, you might measure the perimeter of a playing card in inches, a lake in feet, and a country in miles. You can find the perimeter, or the outside boundary of something, of almost anything! A room in your house, a parking lot, the block that you live on, and more! Perimeters can be any size and include straight or curved lines. Students will next learn some of the ways we use perimeter. We use it to figure out what length of fence we need for a house, the right size picture frame to buy, or how long a track for running is!

Finding Perimeter

Next, students will discover how to find perimeter. First, you have to decide whether you want to measure the perimeter in inches, feet, or miles. The lesson provides the example of a playing card. Because playing cards are small, you would use inches to measure the perimeter. All you have to do is add the lengths of the four sides of the card together. The four sides in this example are 3, 3, 2, and 2 inches, so the perimeter is 10 inches.

You can also find the perimeter of squares or rectangles when you don’t have the measurements of all of the sides. The lesson provides examples of both squares and rectangles with missing measurements. Squares have four sides of equal length. In the example, one side is 4 inches, so the perimeter is 16 inches. Rectangles have sides that have the same measure as their opposite. The example rectangle shows on side with 2 inches and one with 5 inches, so the total perimeter is 14 inches.

To measure shapes on paper, you can first use a finger to trace the outside edge of the shape, making sure you can identify the length of each side. You can start to measure larger perimeters by walking along them. You can find the perimeter of any shape, includes circles! We call the perimeter of a circle the circumference. The lesson includes some examples that show how to find the perimeter of various different shapes. You can also use string to find a perimeter! Measure the string and then wrap it around the outside boundary of the shape or object you want to measure. You can also use a measuring tape in the same way! Finally, the lesson notes that it’s important to keep track of each side of the object you’re measuring to make sure you don’t miss any.


The Introduction to Perimeter lesson plan includes three worksheets: an activity worksheet, a practice worksheet, and a homework assignment. You can refer to the guide on the classroom procedure page to determine when to hand out each worksheet.


Students will work in pairs to complete the activity worksheet. To begin, they will cut string to three different lengths: 1 inch, 5 inches, and 10 inches. They will then use the string to measure the perimeter of various objects, like a round wall clock, desk top, classroom door, and chalkboard. They will sketch each object and write down the measurements of each of its sides. Next, they’ll calculate the total perimeter of each object and write it down on the worksheet, rounding it to the nearest inch.

Students can work either alone or in groups of three for this activity if you’d prefer.


The practice worksheet asks students to complete two exercises. The first asks them to find the perimeter of various shapes when given the length of all of the sides. The second asks them to fill in the blanks to answer questions about perimeter and what they’ve learned during the lesson.


For the homework assignment, students will look at a road map and answer questions about it. These questions involve finding the perimeter of various parts of the map. They will also have to solve a perimeter word problem.

Worksheet Answer Keys

This lesson plan includes answer keys for the practice worksheet and the homework assignment. No answer key is provided for the activity worksheet. If you choose to administer the lesson pages to your students via PDF, you will need to save a new file that omits these pages. Otherwise, you can simply print out the applicable pages and keep these as reference for yourself when grading assignments.

Additional information


1st Grade, 2nd Grade, 3rd Grade, 4th Grade


Math, Video

State Educational Standards


Lessons are aligned to meet the education objectives and goals of most states. For more information on your state objectives, contact your local Board of Education or Department of Education in your state.

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blooming T.

introduction to perimeter

very good resource, fully detailed and easy to understand

Erica L.

Very Helpful

Very Helpful and resourceful.

Kathleen F.

Great Lesson

I was able to use different parts of the lesson to give me new ideas on how to teach area and perimeter!

Eileen T.


My kids love the activity and the lesson plan keeps them engaged.