12/24/2016
(67) Perimeter review | Perimeter | Area and perimeter | Geometry | Khan Academy
Perimeter review
Review the basics of perimeter and try some practice problems.
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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?
10 m
10 m
8m
18 m
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12/24/2016
(67) Perimeter review | Perimeter | Area and perimeter | Geometry | Khan Academy
We can find the perimeter by adding all of the side lengths.
10 m
10 m
8m
18 m
Perimeter = 18 + 8 + 10 + 10
Perimeter = 46 m
Example 2:
What is the perimeter of the regular pentagon?
9 cm
We can find the perimeter by adding all of the side lengths.
All sides of a regular pentagon are the same length.
https://www.khanacademy.org/math/geometry-home/geometry-area-perimeter/geometry-perimeter/a/perimeter-review
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12/24/2016
(67) Perimeter review | Perimeter | Area and perimeter | Geometry | Khan Academy
9 cm
9 cm
9 cm
9 cm
9 cm
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
6 cm
8 cm
10 cm
Check
Explain
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12/24/2016
(67) Perimeter review | Perimeter | Area and perimeter | Geometry | Khan Academy
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
Check
Explain
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12/24/2016
(67) Perimeter review | Perimeter | Area and perimeter | Geometry | Khan Academy
Want to try more problems like this? Check out these exercises:
Find a missing side length when given perimeter
Perimeter word problems
https://www.khanacademy.org/math/geometry-home/geometry-area-perimeter/geometry-perimeter/a/perimeter-review
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