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3rd grade
Course: 3rd grade > Unit 11
Lesson 1: Perimeter- Perimeter: introduction
- Perimeter of a shape
- Find perimeter by counting unit squares
- Find perimeter by counting units
- Finding perimeter when a side length is missing
- Find perimeter when given side lengths
- Finding missing side length when given perimeter
- Perimeter review
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Perimeter review
CCSS.Math:
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 start color #11accd, start text, b, l, u, e, end text, end color #11accd.
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.
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.
Want to learn more about calculating perimeter? Check out this video.
Practice set 1: Calculate perimeter
Want to try more problems like this? Check out these exercises:
Find perimeter when given side lengths
Find perimeter by counting unit squares
Find perimeter when given side lengths
Find perimeter by counting unit squares
Practice set 2: Challenge items
Want to try more problems like this? Check out these exercises:
Find a missing side length when given perimeter
Perimeter word problems
Find a missing side length when given perimeter
Perimeter word problems
Want to join the conversation?
- If two or more sides of a shape is unknown, what can you do to figure that out?(52 votes)
- 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(12 votes)
- How will I use this in real life?(25 votes)
- well... if you r going to build a house u will need to know the perimeter.(3 votes)
- its a bit challenging though. you really need analyzing skills for it ahaha.(9 votes)
- 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.(8 votes)
- 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(7 votes)
- Yeah, I agree, Mr. Taylor—I got confused, the angle change puzzled me, but I realized my mistake and corrected it.(11 votes)
- how can you see perimeter in 3D polygons(11 votes)
- Upvote me if you have friends(7 votes)
- If two or more sides of a shape is unknown, what can you do to figure that out?(2 votes)
- Well, it depends on the shape, really...(4 votes)