We hope you enjoyed trying 5 lessons!
Become a member to get full access to our entire library of learning videos, reading material, quiz games, simple DIY activities & more.
Plans & PricingWelcome to Our New Math Lessons!
Your subscription is currently only to our science lessons.
5 Free Math Lessons Left
Add Math To My Plan (+$50/yr)We hope you enjoyed sampling 5 Math Lessons!
Your subscription is currently only to our science lessons.
Add Math To My Plan (+$50/yr)0 Free Math Lessons Left
Oops! It looks like your security settings are blocking this video 🙁
If you are on a school computer or network, ask your tech person to whitelist these URLs:
*.wistia.com, fast.wistia.com, fast.wistia.net, embedwistia-a.akamaihd.net
Sometimes a simple refresh solves this issue. If you need further help, contact us.
Introduction to Perimeter
Sorry, student links are only for classroom & school accounts.
Please login to generate a student link.
Generate Student Link
- Show lesson plan & teacher guide
- Show answers to discussion questions
- Show video only
- Allow visiting of other pages
- Hide assessments
What you will learn from this videoWhat you will learn
- We’ll learn that perimeter is the distance around a shape.
- That we can use perimeter to figure out unknown sides of an object.
- And that knowing the perimeter can help us build a fort, have a party, and even hang our favorite picture.
- Discussion Questions
Before Video
What would you measure with a ruler or yardstick?ANSWERThe length of an object.
The length of a pencil, the length of the room, the length and width of a desk.
Triangle; rectangle, square, parallelogram, or quadrilateral; pentagon; hexagon; octagon.
A 6-sided polygon with all sides the same length. Sample answer: You could measure all 6 sides.
Measure around the outside of the rectangle.
After Video
What are we finding when we measure all of the outside edges around a shape? ANSWERPerimeter.
You can add the given measurement 4 times because all 4 sides of a square are equal. Or you could multiply the known length by 4, since all 4 sides are the same length.
The missing sides are 10 meters and 20 meters.
Add 100 cm eight times; or multiply 8 times 100 cm.
ANSWERThe missing side is 13 cm. "I added the lengths of all sides given, and then subtracted the total from the given perimeter, 58 cm."
- Vocabulary
- Hexagon DEFINE
A 6-sided figure.
- Pentagon DEFINE
A 5-sided figure.
- Polygon DEFINE
A plane figure with at least three straight sides and angles.
- Perimeter DEFINE
The distance around a shape.
- Regular Polygon DEFINE
A polygon that has all sides of equal length and all angles equal.
- Rectangle DEFINE
A 4-sided figure with two pairs of equal sides and four right angles.
- Square DEFINE
A 4-sided shape with 4 sides of equal length and four right angles.
- Hexagon DEFINE
- Reading Material
- Practice Word Problems
- Practice Number Problems
- Lesson Plan
- Teacher Guide
Explore Our Science Topics
Explore Our Science Topics
Select a Google Form
Choose a way to play this quiz game
- Questions appear on the teacher's screen. Students answer on their own devices.
Choose a Renewal Option
- Download Invoice
Science & Math
$_{/yr}
- Download Invoice
Science Only
$_{/yr}
Level 1
What is the perimeter of a rectangle that has 2 sides labeled: 75 cm and 55 cm?
Level 2
A shape has a perimeter of 190 cm. You labeled all sides but one and forget what the measurement is. You have these measurements written down: 30 cm, 40 cm, 20 cm, 70 cm. What is the length of the last side?
Level 3
A rectangular dining room table has side lengths 3 m and 6 m. Jo multiplied 3 m × 6 m to find the perimeter of the table. Is Jo right? Tell why or why not.
"My students loved the videos. I started the video subscription in May and used them as a review before the state test, which I know contributed to 100% of my class passing the state test."
Rhonda Fox 4th Grade Teacher, Ocala, Florida• No credit card required •
Start Your Free Trial
Free for 14 days, then only $10 CAD/month.
- Unlimited access to our full library
of videos & lessons for grades K-5. - You won’t be billed unless you keep your
account open past your 14-day free trial. - You can cancel anytime in 1 click on the
manage account page or by emailing us.
- Unlimited access to our full library of videos & lessons for grades K-5.
- You won't be billed unless you keep your account open past 14 days.
- You can cancel anytime in 1-click on the manage account page.