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Square perimeter 22, find the side

Step by step, with the reason for every step · Work backwards · Geometry

Step by step

The question

Question: find the side s of a square with perimeter 22.

1 Write the rule

All four sides of a square are the same.

So the perimeter is 4 times the side.

So 4 × s = 22.

4 × s = 22

Careful!

The square root is for the area.

The perimeter is 4 sides added, so we divide by 4.

Careful: not s = √22 ✗

2 Remove the × 4

We want s by itself.

The times 4 is in the way.

To remove times 4, we divide by 4.

We do it on both sides.

Why both sides?

The = sign means both sides are the same amount.

If we change only one side, they are not the same any more.

4 × s4 = 224

4 divided by 4 is 1.

So just s is left.

22 divided by 4 is 5.5.

So the side is 5.5.

s = 5.5

3 Check

Let's check: 4 times the side.

4 × 5.5 = 22

We get 22, the perimeter.

So the side is right!

Let's look back.

First: write the rule.

Then: remove the × 4.

Last: check.

Answer
s = 5.5

Your turn

Try this one yourself, then check:

Find the side.
Show the answer
s = 6

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