If two or more sides of a shape is unknown, what can you do to figure that out?

If you want to figure it you have to see the othr stuff first then you would figure it out but if not i don't know it worked for me

How will I use this in real life?

well... if you r going to build a house u will need to know the perimeter.

can you calculate this problem please. A piece of wire 80cm long is bent to form a rectangle. Find the dimensions of the rectangle so that its area us as large as possible.

A square will give most area. Square with four sides of 20cm each. Therefore to find area we multiply length * width: 20 * 20 = 400 cm²

If two or more sides of a shape is unknown, what can you do to figure that out?

Well, it depends on the shape, really...

Main content

Perimeter review

Google Classroom

Review the basics of perimeter and try some practice problems.

What is perimeter?

Perimeter is the distance around the outside of a two-dimensional shape.

The perimeter of the shapes below is shown in

blue

Want to learn more about the concept of perimeter? Check out this video.

How do we calculate the perimeter of a shape?

To find the perimeter of a shape, we add all of the shape's side lengths.

Example 1:

What is the perimeter of the trapezoid?

We can find the perimeter by adding all of the side lengths.

Perimeter = 18 + 8 + 10 + 10

Perimeter = 46 m

Example 2:

What is the perimeter of the regular pentagon?

We can find the perimeter by adding all of the side lengths.

All sides of a regular pentagon are the same length.

Perimeter = 9 + 9 + 9 + 9 + 9

Perimeter = 45 cm

Want to learn more about calculating perimeter? Check out this video.

Practice set 1: Calculate perimeter

Problem 1A

What is the perimeter of the triangle?

centimeters

Want to try more problems like this? Check out these exercises:
Find perimeter when given side lengths
Find perimeter by counting unit squares

Practice set 2: Challenge items

Problem 2A

The perimeter of the figure is

50 cm

What is the length of the missing side?

cm

Want to try more problems like this? Check out these exercises:
Find a missing side length when given perimeter
Perimeter word problems

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Vignesh Sivakala Vipin
Posted 6 years ago. Direct link to Vignesh Sivakala Vipin's post “If two or more sides of a...”
If two or more sides of a shape is unknown, what can you do to figure that out?
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(62 votes)
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- hudsonbryant
  Posted 3 years ago. Direct link to hudsonbryant's post “If you want to figure it ...”
  If you want to figure it you have to see the othr stuff first then you would figure it out but if not i don't know it worked for me
  Comment on hudsonbryant's post “If you want to figure it ...”
  (9 votes)
202540
Posted 6 years ago. Direct link to 202540's post “How will I use this in re...”
How will I use this in real life?
Button navigates to signup pageComment on 202540's post “How will I use this in re...”
(27 votes)
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- b22adyapandeya
  Posted a year ago. Direct link to b22adyapandeya's post “well... if you r going to...”
  well... if you r going to build a house u will need to know the perimeter.
  Comment on b22adyapandeya's post “well... if you r going to...”
  (6 votes)
AbigailC
Posted a year ago. Direct link to AbigailC's post “i like math”
i like math
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(18 votes)
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- Charlie
  Posted a year ago. Direct link to Charlie's post “Same”
  Same
  Comment on Charlie's post “Same”
  (7 votes)
Pris Deline Macano Love Grey Forever!!!!
Posted 7 years ago. Direct link to Pris Deline Macano Love Grey Forever!!!!'s post “its a bit challenging tho...”
its a bit challenging though. you really need analyzing skills for it ahaha.
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(12 votes)
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BoeJiden
Posted 10 months ago. Direct link to BoeJiden's post “I love this so fun it is ...”
I love this so fun it is so fantastic
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(11 votes)
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- LeahB
  Posted 4 months ago. Direct link to LeahB's post “Why do you put this here ...”
  Why do you put this here why why!
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  (1 vote)
JEan JaNe
Posted 6 years ago. Direct link to JEan JaNe's post “can you calculate this pr...”
can you calculate this problem please. A piece of wire 80cm long is bent to form a rectangle. Find the dimensions of the rectangle so that its area us as large as possible.
Button navigates to signup pageComment on JEan JaNe's post “can you calculate this pr...”
(7 votes)
Answer
- Denis Orlov
  Posted 4 years ago. Direct link to Denis Orlov's post “A square will give most a...”
  A square will give most area. Square with four sides of 20cm each. Therefore to find area we multiply length * width: 20 * 20 = 400 cm²
  Comment on Denis Orlov's post “A square will give most a...”
  (9 votes)
halldav10
Posted a year ago. Direct link to halldav10's post “what is 100x10,000000?”
what is 100x10,000000?
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(4 votes)
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- samhossfield
  Posted a year ago. Direct link to samhossfield's post “A certain number.”
  A certain number.
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  (15 votes)
MarijoseD
Posted 7 years ago. Direct link to MarijoseD's post “how can you see perimeter...”
how can you see perimeter in 3D polygons
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(13 votes)
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Wyatt THE Goat
Posted 3 years ago. Direct link to Wyatt THE Goat's post “If two or more sides of a...”
If two or more sides of a shape is unknown, what can you do to figure that out?
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(4 votes)
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- Jie Ma
  Posted a year ago. Direct link to Jie Ma's post “Well, it depends on the s...”
  Well, it depends on the shape, really...
  Comment on Jie Ma's post “Well, it depends on the s...”
  (3 votes)
risha
Posted 7 years ago. Direct link to risha's post “Yeah, I agree, Mr. Taylor...”
Yeah, I agree, Mr. Taylor—I got confused, the angle change puzzled me, but I realized my mistake and corrected it.
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(9 votes)
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3rd grade (Eureka Math/EngageNY)

Course: 3rd grade (Eureka Math/EngageNY) > Unit 7