# What is the purpose of volume measurement

## Basics of volume and surface calculation

In these explanations you will learn how to measure and compare the size of two right-angled bodies.

### Determine the volume of a body

Every body needs space. You can measure the size of this room (the volume or the volume) in different ways. You can often fill rectangular bodies with cubes. In order to be able to compare the measured values ​​with one another, unit cubes are used (one edge length corresponds to one length unit). The body in which more unit cubes fit has the larger volume.

You cannot determine the volume of irregular or round bodies by counting unit cubes, but you can determine the volume of a hollow body with the help of a measuring cup.

Which vase fits more water in?

If the body is not hollow - that is, it cannot be filled - then there is another way of determining its volume. You immerse the body (for example a stone) in a vessel with water and measure how much the water level rises in the vessel.

### Determine the surface of a body

The surface (or the surface area) of a body is the sum of the areas of all sub-areas.

Some bodies can be cut open at the edges so that you get a coherent network of body surfaces.

The surface of the cuboid

The surface of the cuboid consists of six rectangles. If you add up the areas of these six rectangles, you get the area of ​​the cuboid.

The cuboid network is a flat figure. You can determine its area by laying out the area with it.