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Intro to area and unit squares

Together, we'll explore a video introducing area by comparing two figures' space on a surface. Using unit squares, we'll measure their areas, emphasizing the importance of a unit square for measuring various shapes. Created by Sal Khan.

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  • winston baby style avatar for user Steven Lin
    how does area help the real world
    (37 votes)
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    • orange juice squid orange style avatar for user Dashiell
      I find geometry has many practical uses in everyday life, such as measuring circumference, area and volume, when you need to build or create something. Geometric shapes also play an important role in common recreational activities, such as video games, sports, quilting and food design, ect...
      (13 votes)
  • marcimus purple style avatar for user YUCHEN
    Plz give me 50+ votes then i will give you a lot of votes
    (14 votes)
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  • starky sapling style avatar for user robleang000
    how he finds the amount is by using unit square
    (11 votes)
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    • area 52 blue style avatar for user jachkers
      Using units squared will give you the answer as long as the shape you are measuring can be divided by the area of units squared. So doing this in a mathematical sense without using physical shapes, you would divide the Unit squared by the objects area. Ex. How many times would a 1cm unit go into a 3cm unit, 3 times. Because we multiplied the 1cm unit x3 to get our answer.
      (4 votes)
  • hopper cool style avatar for user Elvis Hoang
    What is it called when it is 4-D(example:3-D,cube units/2-D,square units)?
    (6 votes)
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  • duskpin tree style avatar for user AaryaTheCool
    This is so easy for me because i can just type thisSo 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 than 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 this square, whatever units we're using, we could say it's a one unit. So if its width right over here is one unit and its height right over here is one unit, we could call this a unit square. And so one way to measure the area of these figures is to figure out how many unit 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 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, five unit squares. Let me write this down. So we got 1, 2, 3, 4, 5 unit squares, and I could 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 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 1, 2, 3, 4, 5, 6, 7, 8, 9, 10 of these unit squares. I can cover it. They're not overlapping, or I'm trying pretty close to not make them overlap. You see, you can fit 10 of them. And let me draw the boundary between them, so you can see a little bit clearer. So that's the boundary between my unit squares. So I think-- there you go. And we can count them. We have 1, 2, 3, 4, 5, 6, 7, 8, 9, 10. So we could say the area here-- and 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 10. 10 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, and 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 1 unit by 1 unit. In the future we'll see that it could be a unit centimeter. It could be a 1 centimeter by 1 centimeter squared. It could be a 1 meter by 1 meter squared. It could be a 1 foot by 1 foot square, but then we can use that to actually measure the area of things. This thing has an area of 5 square units. This thing has an area of 10 square units. So this one we can actually say has twice the area. The purple figure had twice the area-- it's 10 square units-- as the blue figure. It takes up twice the amount of space on the screen.

    Plz give me 50+ votes then i will give you a lot of votes
    (6 votes)
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  • blobby green style avatar for user 408448
    how do you find the prminiter
    (4 votes)
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  • mr pants teal style avatar for user Swetha
    What if the square unit is cut in half? Would it be some number .5
    (4 votes)
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  • duskpin tree style avatar for user AaryaTheCool
    This is so easy
    Plz gie me 50+ votes then i wil give you 50 plus votes!
    (6 votes)
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  • blobby green style avatar for user NEHEMIAS
    can i get 3 votes pls🥺
    (5 votes)
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  • blobby purple style avatar for user Mei Ayco
    how do find the area of a triangle?
    (2 votes)
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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 than 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 this square, whatever units we're using, we could say it's a one unit. So if its width right over here is one unit and its height right over here is one unit, we could call this a unit square. And so one way to measure the area of these figures is to figure out how many unit 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 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, five unit squares. Let me write this down. So we got 1, 2, 3, 4, 5 unit squares, and I could 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 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 1, 2, 3, 4, 5, 6, 7, 8, 9, 10 of these unit squares. I can cover it. They're not overlapping, or I'm trying pretty close to not make them overlap. You see, you can fit 10 of them. And let me draw the boundary between them, so you can see a little bit clearer. So that's the boundary between my unit squares. So I think-- there you go. And we can count them. We have 1, 2, 3, 4, 5, 6, 7, 8, 9, 10. So we could say the area here-- and 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 10. 10 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, and 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 1 unit by 1 unit. In the future we'll see that it could be a unit centimeter. It could be a 1 centimeter by 1 centimeter squared. It could be a 1 meter by 1 meter squared. It could be a 1 foot by 1 foot square, but then we can use that to actually measure the area of things. This thing has an area of 5 square units. This thing has an area of 10 square units. So this one we can actually say has twice the area. The purple figure had twice the area-- it's 10 square units-- as the blue figure. It takes up twice the amount of space on the screen.