Finding the Perimeter of a Rectangle
By John Brooks, M.A.
You can find John on Veditz at https://veditz.org/john-brooks
You can find John’s ASL Video lesson on Finding the Perimeter of a
Rectangle at: https://support.veditz.org/hc/en-us/articles/223287827
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Hello! Welcome to this video! In this video, we will explore the
question… How do we find the perimeter of a rectangle?
What does perimeter mean? Suppose we have a rectangle. We start on
the upper left corner. How long is that? That is called perimeter.
Measuring the outside length.
Now let’s talk a little bit about what is a rectangle? A rectangle has four
sides. Let’s take a look at this picture. That is not a rectangle. This is
because all four sides are the same. Rectangles are a little different.
The opposite sides are equal. This means the left and right sides are the
same. The top and bottom sides are the same. Here is another picture.
This is a rectangle.
Now that we’ve explained perimeter and rectangles… Let’s find out how
to get perimeter.
Here is an example.
Suppose we have a rectangle. One side has 3 inches clearly marked. We
have 8 inches marked on the bottom. Remember, the rule opposite sides
© 2016 Veditz.org and John Brooks
are equal on a rectangle. This means the side opposite of 3, is also 3. And
the side opposite of 8, is also 8. So let’s go ahead and mark these sides.
Now we have all four sides clearly marked. We can use that information
to solve. We can add all sides. This means 3 + 8 + 3 + 8. And the answer
is… 22 inches. That’s one way to do it.
Now the second way may be easier for some. Take both sides and
remember we started with only two sides. The sides opposite of these
two are the same. So we can multiply both sides by 2. This means 3
times 2. And 8 times 2.
Then we add up the results. This gives us the same answer. 22 inches.
So we have an idea of how to find perimeter for a rectangle. Remember
one more tip, opposite sides are equal on a rectangle.
Thank you for watching! End
© 2016 Veditz.org and John Brooks