If you're seeing this message, it means we're having trouble loading external resources on our website.

If you're behind a web filter, please make sure that the domains *.kastatic.org and *.kasandbox.org are unblocked.

Main content
Current time:0:00Total duration:4:17

Video transcript

so we've got two figures right over here and I want to think about how much space they take up on your screen and this idea of how much space something takes up on a surface this idea is area so right when you look at it it looks pretty clear that this purple figure takes up more space on my screen than this blue figure but how do we actually measure it how do we actually know how much more area this purple figure takes up then this blue one well one way to do it would be to define a unit amount of area so for example I could create a square right over here and the square whatever units were using we could say it's a 1 unit so if its width right over here is 1 unit and its height right over here is 1 unit we could call this a unit square a unit square and so one way to measure the area of these figures is to figure out how many units squares I could cover this thing with without overlapping and while staying in the boundaries so let's try to do that let's try to cover each of these with unit squares and then and essentially we'll have a measure of area so I'll start with this blue one so we could put 1 2 3 3 4 5 5 unit squares let me write this down so we got 1 2 3 4 5 unit squares and I can draw the boundary between those unit squares a little bit clearer so we have 5 unit squares and so we could say that this figure right over here has an area the area is 5 we could say 5 unit squares the more typical way of saying it is that you have 5 square v square units that's the area over here now let's do the same thing with this purple figure so with the purple figure I could put one two three four five six seven eight nine ten of these unit squares I can cover it they're not overlapping where I'm trying pretty close to not make them overlap you see can fit ten of them and let me draw the boundary between them so you can make them a little you can see it a little bit clearer so that's the boundary between my unit squares between my unit squares so I think there you go and we can count them we have one two three four five six seven eight nine ten so we could say the area here let me actually divide these with the black boundary too it makes it a little bit clearer than that blue so the area here for the purple figure we could say so the area here is equal to ten ten square 10 square units so what we have here we have an idea of how much space does something take up on a surface and you could eyeball it say hey this takes up more space but now we've come up with a way of measuring it we can define a unit square here it's a one unit by one unit in the future we'll see that it could be a it could be a unit centimeter it could be a one centimeter by 1 centimeter square it could be a one meter by one meter square could be a one foot by one foot square but then we can use that to actually measure the area of things this thing has an area of five square units this thing has an area of 10 square units so this one we can actually say is twice has twice the area the purple figure had twice the area it's ten square units as the blue figure takes up twice the amount of space on the screen