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## Basic geometry and measurement

# Surface area versus volume

CCSS.Math:

A 3D figure has both surface area and volume measurements, but we use them for different purposes. Learn the difference and when to use each.

## Making sense of units

We have many types of units. Some measure length in 1 dimension. Some measure area in 2 dimensions. Others measure volume in 3 dimensions. Units come in larger and smaller sizes, too.

## Key measurement terms

**Length**is a 1-dimensional measurement. It tells us the number of

*units*between one point and another. We measure length in units like centimeters, inches, feet, meters, kilometers, and miles.

**Perimeter**is a special example of length. It is the distance around a closed 2D figure.

**Area**is a 2-dimensional measurement. It tells us the amount of space enclosed in a 2D figure. We measure area in

*square units*such as square centimeters (start text, c, m, end text, squared), square inches, and square meters.

**Surface area**is a special example of area. It tells us the number of*square units*it would take to cover the faces of the 3D figure.

**Volume**is a 3-dimensional measurement. It tells us the number of

*cubic units*it would take to fill a 3D figure. We measure volume in units like cubic centimeters left parenthesis, start text, c, m, end text, cubed), cubic inches, and cubic meters. For liquids, we sometimes use different volume units, such as milliliters, cups, liters, and gallons.

Notice, this means that we can measure both the surface area and the volume of a 3D figure, but they tell us different things about the figure.

## Distinguishing area and volume

Let's consider the same situations from before, this time to decide whether which type of measurement makes the most sense.

The same 3D figure can have both surface area and volume.

Let's contrast the volume and surface area of two figures.

So the figures have the same volume, but different surface areas!

The opposite is possible, too. Two figures could have the same surface area, but different volumes.

## Try it out!

## Want to join the conversation?

- why is there so many on on question?(11 votes)
- Isn’t that good for practice?(15 votes)

- Can everyone pls upvote this ☺️(14 votes)
- why the Surface area is 32(10 votes)
- idk but i also got 32 on the first try by adding the 4 middle parts(2 votes)

- What the heck is this its so hard🥲(9 votes)
- ikr why do we need to learn this(1 vote)

- am abt to pass out my brain can't support this much math💀(8 votes)
- this dont make sence(6 votes)
- What is 3x3x3x3x3x3x3x3x3x3x3x3(3 votes)
- 3x3x3x3x3x3x3x3x3x3x3x3= 531441(5 votes)

- This is so simple yet so, so very annoying lol(5 votes)
- If anyone can tell me which question dose not make sense to you I am glad to help!(5 votes)
- I dont know what to ask(5 votes)