Cross section (geometry) facts for kids

A 3-D view of a beverage-can stove with a cross section in yellow

Imagine you have an object, like an apple or a loaf of bread. If you cut that object straight through, the flat surface you see on the inside is called a cross section. It's like looking at a slice of something.

This idea helps us understand what's inside objects without breaking them apart completely. It's used in many areas, from science to art.

What is a Cross Section?

A cross section is simply the shape you get when you slice through a 3D object. Think of cutting a cucumber. The round slice you hold is a cross section of the cucumber. It shows you the inside of the object at that specific point.

Cross Sections in Geometry

In geometry, a cross section has a more exact meaning.

• If you have a 3D shape, like a ball or a cube, and you cut it with a flat surface (a plane), the shape where the cut happens is the cross section.
• For example, if you slice a sphere (a ball) with a flat plane, the cross section will always be a circle.
• If you slice a cube, you might get a square, a rectangle, or even a triangle, depending on how you cut it!

Cross Sections in Drawings

Cross sections are also very important in technical drawings and blueprints.

• They help people see the hidden parts of an object.
• For example, a floor plan of a house is a type of cross section. It's like cutting the house horizontally and looking down from above. This shows you where the rooms, walls, and doors are.
• Engineers and architects use cross sections to show how things are built inside, like the parts of an engine or the layers of a building.

Images for kids

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  A cross-section view of a compression seal

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  Pinus taeda cross-section showing annual rings, Cheraw, South Carolina.

See also

• Orthographic projection
• Plans (drawings)

In Spanish: Sección (geometría) para niños