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Volume of a rectangular prism

If you want to know how much stuff you can cram into a box, finding its volume is key. To calculate the volume of a box, you need to know its height, width, and depth. You can find the volume by multiplying these three dimensions together. This formula works regardless of the units you are using (e.g. meters, feet), he method is the same - just make sure your units match up! Created by Sal Khan.

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  • winston baby style avatar for user Otto Buff
    why do you multiply the lengths of the sides
    (38 votes)
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  • male robot johnny style avatar for user 25harrisdevin
    At , He said that it was in meters, but how could it be converted to another measurement type?
    (15 votes)
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    • orange juice squid orange style avatar for user Vic
      You would just convert the dimensions. In this instance, it is 6m by 7m by 8m.
      6m is about 19.685 feet
      7m is about 22.965 feet
      8m is about 26.246 feet

      Then just do what you would regularly do when finding volume - base * height. :)
      Best of luck to you!
      (26 votes)
  • duskpin ultimate style avatar for user Ashley
    I'm confused, will someone explain how to do this plz?
    (14 votes)
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    • blobby green style avatar for user Shazia Zehra
      Volume is easy. For example:
      Height: 5 in.
      Width: 5 in.
      Length: 5 in.
      You can multiply length by width or width by length. If you do length by width you will get 25 and the height is 5 so multiply 25x5=125 so the volume is 125 cubic inches. Hope it helps!
      (8 votes)
  • boggle yellow style avatar for user Izabella De Palma
    help me i don't get this at all an i have a test tomorrow!
    (11 votes)
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    • primosaur ultimate style avatar for user avisarus
      Volume for cubes and rectangular prisms are just
      Volume = Length * Width * Height.

      All you need to do now is plug the numbers in and use the right units.

      If I have a box and it's 8in x 2 in x 9 in I'd do
      8*2*9 = 144, but what units do I use?
      My units were all in inches and because I did in*in*in my units are in^3.
      It's the same for any unit of volume it's all __ ^3.
      (15 votes)
  • female robot ada style avatar for user Barzallo, Mila
    What would be the easier strategy to find the volume of a rectangular prism?
    (6 votes)
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    • aqualine ultimate style avatar for user j
      Good question.
      The formula to solve for the volume of a rectangular prism is LxWxH.
      ( Length x Width x Height )

      Let me demonstrate my thinking with this example.
      Let's just assume that these are the numbers in the word problem, and we have to solve for V ( Volume ).
      5 inches is the Length
      8 inches is the Width
      3 inches is the Height

      It's pretty simple.
      Just multiple all three of numbers using a calculator, or you can do it on paper, lining up all the numbers vertically.

      The sum of all three numbers ( 5 x 8 x 3 ) equals 120. Therefore, the volume of the rectangular prism is 120³.

      Hint: Whenever solving for the Volume of a 3D shape, remember to cube your final answer. Like this: 120³

      Hope this clears out your confusion.
      (11 votes)
  • aqualine ultimate style avatar for user Lenore
    I'm very confused because looking back at my work, I only have two identified sides (technically). I have the width and the base area which is confusing because the base area says that it's measured in units squared, so do I divide the base area by two then multiply the width by the base area by the base area? or no?
    (6 votes)
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    • stelly blue style avatar for user Kim Seidel
      The video tells you the formula is:
      Volume = Length (Width) (Height)
      If you multiply any 2 of these measurements, you get the area of one side (comparable to your base). Once you multiply the the 3rd measurement, you get the volume

      So, in your situation, someone as already multiplied 2 of the dimensions for you since you were given the area of the base. You just need to multiply your 2 numbers to get the volume.

      Hope this helps.
      (7 votes)
  • blobby green style avatar for user kilaruvaibhav
    Can I get more help on this? I'm not quite sure I understand.
    (6 votes)
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  • duskpin ultimate style avatar for user Yulee Oh
    Why would the first answer be 336 m3 instead of 336 m2?
    (2 votes)
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    • mr pants teal style avatar for user Aeris L
      The first answer is 336 m3 instead of 336m2 because a rectangular prism is not flat and 2 dimensional, it is 3 dimensional it takes up space, think of it as a box. A box is not flat, rather it is three dimensional it takes up space. Compared to a flat rectangle it has volume.
      (4 votes)
  • aqualine ultimate style avatar for user preyritlakhani
    Um... How come Sal can rotate the cubes but so far we never got to?
    (3 votes)
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  • marcimus pink style avatar for user abddisaalulla
    can you make it easy for me and other because I don't get it so make it easy for us so we can understand you. Make it easy From BLEN
    (2 votes)
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Video transcript

What is the volume of this box? Drag on the box to rotate it. So this is pretty neat. We can actually sit and rotate this box. And here it looks like everything's being measured in meters. So we want to measure our volume in terms of cubic meters. That's going to be our unit cube here. So when we want to think about how many cubic meters could fit in this box, we've already seen examples. You really just have to multiply the three different dimensions of this box. So if you wanted the number of cubic meters that could fit in here, it's going to be six meters times 8 meters times 7 meters which is going to give you something in cubic meters. So let's think about what that is. 6 times 8 is 48. Let me see if I can do this in my head. 48 times 7, that's 40 times 7, which is going to be 280 plus 8 times 7, which is 56, 280 plus 56 is going to be 336. Let's check our answer. Let's do one more of these. So what's the volume of this box? We'll once again, we have its height at six feet. Now everything is being measured in feet. We have it's width being four feet. So we could multiple the height times the width of four feet. And then we can multiply that times its depth of two feet. So 6 times 4 is 24 times 2 is 48 feet. 48, and I should say cubic feet. We're saying how many cubic feet can fit in here? When we multiply the various dimensions measured in feet, we're counting almost how many of those cubic feet can fit into this box.