Finding the perimeter & physical education

Standards Taught


Recognize and draw shapes having specified attributes, such as a given number of angles or a given number of equal face

CCSS.MATH.CONTENT.3.MD.D.8 Solve real world and mathematical problems involving perimeters of polygons


45 – 50 minutes depending on the time you allot to students for measuring objects and for playing the game.

Technology Required

Making Camp Premium plays in any browser, so, of course, on Chromebooks. It can also be downloaded on phones or tablets and played offline by students who have limited Internet access. The teacher will need a computer, for showing to students learning from home, and a projector if showing videos in the classroom. If the classroom does not have access to a projector, the videos can be skipped. A phone or tablet with a measuring app is optional. If unavailable, students can use a ruler or tape measure instead. NOTE: The measure app comes on iPhone/ iPad by default but for an Android device you’ll need to install some type of measuring app.


Finding the perimeter activities can be fun in school or out. This is an activity recommended for children learning at home, so the instructions below target what you would send to parents, but this activity can be easily adapted for in-school use as well. Best of all, it combines math with P.E. ! Students watch a video, find the length and width of 10 objects and compute the perimeter. After the hands-on activity, students watch another video to reinforce the concept and then play the Making Camp Premium game to practice their multiplication and division.

Materials needed:

  1. A piece of paper
  2. A pen or pencil
  3. A phone or tablet – if not available, a measuring device like a ruler, measuring tape or yardstick can be used instead.
  4. Making Camp Premium (available online and for download on iOS and Android devices)

Lesson Plan

Step 1: Watch the perimeter video

How to find the perimeter of polygons – 2:21

As you might guess from the title, this video explains how to find the perimeter of an object and how to determine if a shape is a polygon.

Step 2. Make a table like in the example below

OBJECTLength     Width     
Top of a box
Seat of a chair    

You can have a Google Doc you share with students with the table in the instructions. However, we recommend that students create their own table with a piece of paper because they are going to be wandering around the house or classroom and it is much easier to carry a piece of paper with you than a laptop.

For this exercise, every object should be a rectangle. Be prepared for the question,

“Is a square a rectangle?”

– every third-grader , ever

Yes. Yes it is. If you want to get technical about it, a rectangle is a quadrilateral with four 90 degree angles. Or you could just say yes, a rectangle is a shape with four sides that are not slanted and a square definitely has four sides and is not slanted.

Step 3. Go measure 10 rectangles in the house

This is where the physical education comes in. Tell the student he or she has 10 minutes to complete the table with 10 items. An item can be as small as a box of candy or as big as the floor of a room. For each rectangle, write down the name of the object, the length and the width. Just put the whole number. If it says 18 1/4 or 18 1/2 just put 18. You may be tempted to tell the student to just round it but remember, he or she may not have learned fractions yet. That’s a lesson for another day.

If you don’t happen to have a ruler, yardstick or tape measure, your phone may already have a Measure app. This comes by default with an iPhone and if you don’t see it right away look in the Utilities folder. Most kids this age take any opportunity they can get to get hold of a parent’s phone. In school, you can use iPads or go old-timer and use a ruler.

To use it, point at a surface and click to select a point. Then, move the phone until you are at the end of what you want to measure.

Depending on how much exercise you want your child to get, the size of your house and how much peace you need (I won’t judge you), you may want to add a few rules like:

  • None of the objects can come from the room you are currently in.
  • They need to find rectangles in at least 3 different rooms
  • They need to find at least one rectangle in the backyard/ garage/ basement.

Once you have shown your child how to use the measure app and they have the table and a pencil, set the alarm on your phone and tell them to go. The alarm will go off when the 10 minutes are up.

Check their number of rectangles and if they are a few short give an extra 2- 5 minutes to find the rest.

Don’t have an iPhone or iPad?

The Ruler app can be downloaded free from Google Play and used to measure small objects. It only works to the size of your device but it is still easy to use and fun. There are apps in Google Play similar to the iPhone Measure app but these are not available on all Android phones.

Step 4 Watch another video on perimeter

Why? Because experience shows that students often don’t remember something if they only heard it once.

Step 5: Compute the perimeter for each object you have measured

OBJECTLength     Width     
Top of a box84
Seat of a chai r     1812

Your student does this, not you. You’ve already completed elementary school.

Step 6: Play Making Camp Premium

Making Camp Premium logo

Tell students that these videos came from Making Camp Premium and now that they have finished the rest of the assignment they have 10 minutes to play.

State Standards

Minnesota Math Standard – Describe, compare, and classify two- and three-dimensional figures according to number and shape of faces, and the number of sides, edges and vertices (corners).

Minnesota Math Standard – Find the perimeter of a polygon by adding the lengths of the sides.