(upbeat music) - Hey, everybody.

Welcome back to "Rise and Shine."

You know, I'm here working on a playhouse that I am building and one of the things that I'm working on is figuring out the perimeter of the playhouse.

Let me show you what I mean.

When we're talking about perimeter, perimeter means the outside distance around something.

So if I said I'm going to walk the perimeter of a building, I'm going to walk around the outside of a building.

Or if I'm going to measure the perimeter of a square, like we have here, I'm going to measure each outside side length, and I'm going to add them all up together and figure out what's the total distance around the outside.

And that's the perimeter.

So let's do one.

So if I have a square here, and I know that the side length is, let's say five inches, so five inches here.

Well, that means if it's a square, you know every side's going to be the same.

So five and five makes 10, but you've got to do every side, so that's four sides.

So 10, 15, and 20.

We know that the outside distance, or the perimeter of that shape would be 20 inches.

So now let's look at our plans here.

What we have for my drawing, and this is a model.

A model is a drawing or something that kind of helps us scale something down so we can work on it.

'Cause if I'm going to make this playhouse, it needs to be a little bit bigger than what's on this poster, right?

So that people can actually fit inside.

But the model helps us see so we can do some working and planning on it ahead of time.

So here's our playhouse, and it's going to be a rectangular shape.

So if I want to find the perimeter of our playhouse, what I'm going to do is I'm going to measure each of those sides just like we did on the square.

So we need a tool to measure it.

We have measuring tapes, rulers, I've got a yard stick here, and that's what I'm going to use.

And as I go, I'm going to measure this in inches.

So that's one of the ways we could measure.

And if I hold it up, I've got to make sure I get it right on the line.

And as I see that it ends up being 15 inches across the top of our rectangle.

So I'm just going to write that down so I can remember that that top side is 15 inches.

Now I'm going to measure the side.

And as I go to measure the side, I'm going to make sure that I'm starting right at the edge, go down, and it's about 10 inches.

So 10 inches down the side.

Now rectangles, we know that those opposite sides are going to be the same length.

I could measure it and make sure, and, okay, it turns out to be just right.

So we've got another 15, and then that other side is 10.

Now to actually calculate the perimeter, we're going to have to add up those numbers together and see what it comes out to be.

So 15 and 10, so if I skip count by tens from 15, that's up to 25.

And now I've got another 15.

So here's a harder one, but remember, 15 is just a 10 and a five.

So if I break that apart, 25 and 10 is 35, add that five, there's 40, and then add 10 more, and we're at 50.

50 inches for my model playhouse right here.

And that's perimeter, the outside distance.

That was fun and thank you for joining me.

(upbeat music)