This is part 2 of our video series on finding the perimeter of plane shapes. Here is a formula sheet for finding the perimeter of plane shapes Perimeter formulas plane shapes

The formula for finding the perimeter of a square is four times one side or 4s

**Problem 1**What is the perimeter of a square that has a side of 8 units?

**Step 1**

**.**4*8 =32 units

**Problem 2**What is the perimeter of a square in which you only know the diagonal length of 10 units.

**Step 1.**Inside a square you have a 45-45-90 right triangle. Therefore you use the 45-45-90 rule to find the length of one side.

**Step 2**Then to find the perimeter multiply 4 times five square root two, which equals twenty square root two.

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