Find perimeter of shape

How to find perimeter???

Perimeter is the total distance around outside of a 2D shape.
You can calculate it by adding together all the lenght of shape.












The perimeter = 
7 cm + 9 cm + 12 cm = 28 cm

How to calculate the perimeter of A triangle :
- This is easy to find the parimeter you just need to add up the lenght of all 3 sides
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you can also learn perimater by song.
it's more interesting for students in third- grade.

I hope these video can inspire teacher and students to joint to find.

GREAT,